Kita Lawan supporters calling for the freeing of jailed opposition leader Anwar Ibrahim are expected to march through downtown Kuala Lumpur today to 'celebrate' the wedding of Prime Minister Najib Abdul Razak's daughter.
Gathering at three meeting points before converging in front of Sogo, they will then march towards the Kuala Lumpur Convention Centre (KLCC) at 4pm.
Malaysiakini brings you the live updates as they take place.
8.06pm: Kita Lawan committee member Fariz Musa has been arrested under the Sedition Act, more than half an hour after the rally ended.
PKR communications director Fahmi Fadzil says Fariz was arrested at Petaling Street around 7.45pm.
He is at the KL Police headquarters and will be brought to the Dang Wangi police station for questioning.
7.25pm: Sogo - Most of the demonstrators have dispersed.
Only about 20 are left in front of Sogo.
There is no police presence, and life in downtown Kuala Lumpur is now back to normal.
7.10pm: Jalan Dang Wangi - About 100 remaining protesters are across the street from the Dang Wangi police headquarters.
They are shouting " Pecat IGP " (Sack the IGP) and calling for the release of PKR leaders Rafizi Ramli and Tian Chua.
Some are also cursing the PM and his wife, their chants incorporating the words 'celaka ' (damn) and ' bangsat' (bastards).
About a dozen policemen are taking shelter from the light rain in the police compound, but only about five are paying attention to the protesters.
About half a dozen unmanned 'black Marias' are parked outside the building.
After about five minutes, the protesters leave.
7pm: Jln Ampang - The police have cleared the barricades they set on Jalan Ampang and have dispersed.
This is after the protestors left the sit-in area peacefully at 6.45pm as agreed between them and the police.
Jalan Ampang traffic returns to normal as the rally is officially over.
6.55pm: Jln Dang Wangi - It is drizzling now. One of the supporters is now hawking raincoats.
The demonstratos have passed through the Dang Wangi LRT station, but have not dispersed.
They are now headed towards the Dang Wangi police headquarters.
6.45pm: Penang - Up north, around 50 protestors including Machang Bubuk state assemblyperson Lee Khai Loon,Kebun Bungah state assemblyperson Cheah Kah Peng and representatives from Samm and PKR Youth stage a protest against GST at Seberang Jaya roundabout.
The group disperses peacefully after holding placards and banners to urge for Najib's resignation for around 45 minutes.
6.45 PM - Jalan Ampang - "All you youths! Today we have won!" Mandeep Singh tells the crowd.
He thanks the police one more time and calls on the protesters to disperse.
They turn around and are now marching towards the Jalan Ampang - Jalan Sultan Ismail intersection.
6.40pm: Jalan Ampang - Around 50 police officers, standing in between police barricades, who were in plain clothes, are now wearing fluorescent police vests.
All of them appear to be prepared to make arrests should the need arise, as they are all seen armed with cable ties.
6.30pm: Jalam Ampang - A foreign teacher expressing her concern to the Kita Lawan organisers over security issues has immediately attracted media attention for a short while.
"I have some very little children in my class, like five years old. You know how they would be if they cannot see their parents as they (the parents) cannot enter the building.
"I respects their right of rally (assembly), just that I would like to express my concerns," says Anna Stevens, a Australian who teaches at British Council, a building next to the protest site.
She returns to the building after getting assurance from the organizers that the sit-in will not take longer than one hour.
6.05pm: Jalan Ampang - Protesters are now 50 metres from the police line.
PKR Youth executive councillor Afzainizam Abd Rahman says police have denied them entry into the KLCC grounds.
The crowd thank the police for keeping them safe, and say they will continue their protest at the present location.
They proceed to hold a sit-in for 45 minutes.
A police source however says they will only be allowed to stay here for half an hour.
6pm: Reports fly that national laureate A Samad Said, or Pak Samad, has been arrested a while earlier. It is later confirmed to be a false alarm.
When contacted, Bersih chairperson Maria Chin Abdullah confirms Pak Samad is safe at home.
"I just got off the phone with him. He is fine. He is at home now, he left early," she tells Malaysiakini .
5.55pm: KLCC - The 'wedding procession' is approaching the end of Jln Ampang.
Over a hundred police personnel are seen linking hands, awaiting the crowd's arrival at the Jalan Ampang and Jalan P Ramlee junction.
The police, standing in three lines, have set up at least three plastic barricades to block the road.
A police truck is also seen on the spot.
An angry protestor shouts at the police, but the police stand still and do not reply to the protestor.
Daylight is falling and the sky grows darker and darker and the roar of a thunderstorm is heard.
Protestors have unfurled a long banner with 'Undur Najib', 'Tangkap Najib' and 'Tangkap Rosmah' written on it.
The crowd has begun singing a modified version of 'Selamat Pengantin Baru', incorporating the lyrics 'Tangkap Najib and Rosmah'
5.40pm: Jln Ampang - A protestor holds a mirror Taoists call "the mirror that reveals the devil" with a note reading, "Rosmah, is today's RM1,200 worth?"
The mirror is traditionally used to reveal the true face of the devil who disguises in human form.
Leong Yung Hong, 21, a student tells Malaysiakini that he copied the idea from Hong Kong.
"This idea I learnt from Hong Kong. Hong Kong people use the mirror to reflect the police, while I am using this to mirror Rosmah," he says.
He explains that it was recently reported that Rosmah had allegedly spent RM1,200 for a hairdo.
Leong, clad in black, also holds a yellow umbrella symbolising the Hong Kong Umbrella revolution.
"I want to remind people of the Hong Kong people's insistence (on protesting against injustice)," he adds.
5.30pm: Jln Ampang - The entourage is now at the Jalan Ampang - Jalan Sultan Ismail junction
Traffic police are present but are not facilitating the crowd.
Disabled activist Isaiah Jacob is among those at the front of the march.
Despite the small turnout, he remains optimistic and hopes more people will turn up for future rallies.
"My advice to the nation: until we have achieved our goals, come and support us. We cannot achieve victory without their support," he tells Malaysiakini .
5.15pm: Jalan Dang Wangi - The crowd makes a quick stop in front of Dang Wangi police headquarters, taking up half the road.
Police have shut the gates, as the crowd chants "Free the detainees!" before breaking into song. About a dozen cops are monitoring the crowd.
Batu MP Tian Chua and PAS deputy president Mohamad Sabu are being held here.
They are spotted among eight people peering out from inside the police headquarters' window, waving at the crowd.
After five minutes the entourage continues with their march towards KLCC.
5.10 pm: Sogo - The 500-strong crowd has begun marching to KLCC.
They are singing the classic Malay wedding song ' Selamat Pengantin Baru ' (Wishing the newlyweds).
Around 20 police officers can be seen in front of Campbell Complex, and they cross the road to where the protestors are coming through.
A slight drizzle begins.
Meanwhile Klang PKR information chief Rizal Mohamad tells Malaysiakini the poor turnout is the result of insufficient planning time.
"Unlike (March 7), the information came late. There wasn't enough time to plan it properly," he says.
He adds the absence of certain leaders who have been arrested has also discouraged people from participating.
5pm: Sogo - PKR Bayan Baru MP Sim Tze Tzin says to the crowd, "This is a critical week. Next week is April fool and GST.
"We are all rising to fight against GST," he says to which someone in the crowd replies, "Greedy tax."
National laureate A Samad Said recites a poem on the spot, and the crowd turns silent and listens attentively.
The crowd starts moving to KLCC after several leaders' speeches as daylight begins to fade.
4.50pm: Sogo - Roughly 500 have gathered so far. Police presence appears to be minimail here from Malaysiakini 's observations.
While many are focusing on the speakers, somewhere in the back, a protester has brought along a toddler with them.
The little girl is sleeping in a pram, decorated with signs that say, "Help! They've stolen my future" and "No tax for pampers".
Several protesters are fanning her to keep her cool, but no one admits to being her parent.
When asked about the potential danger of bringing a toddler to the protest, they shrug it off and say, "We're just following the crowd."
4.30pm: Jalan Raja Laut - A group of ladies clad in black Malay costume are holding gifts, flowers, and cash, claiming this is "in celebration" of Najib's daughter's wedding.
Sogo - The crowd from Masjid Jamek and Dataran Merdeka have arrived, making the group 350 strong.
"Arrest Rosmah! Sack (IGP) Khalid" they shout.
They have also called for the release of Anwar Ibrahim, as well as PKR vice president Rafizi Ramli and activist Hishamuddin Rais arrested yesterday.
4.20pm: Sogo - The small group of protesters has attracted the attention of many shoppers.
Shouts of "Reformasi", "Down with BN" and "End GST," fill the air.
Meanwhile a police source tells Malaysiakini only about eight people are waiting for Mat Sabu at the Dang Wangi police headquarters.
Jalan Raja Laut - The rally has taken on a festive mood, with protesters beating drums and carrying bunga manggar , which fits the group's aim to 'celebrate' Prime Minister Najib Razak's daughter Nooryana Najwa's wedding reception at KLCC today.
4.15pm: Dataran Merdeka - Two groups of protesters, one from Masjid Jamek and the other from Jalan Tunku Abdul Rahman, have arrived at a fountain next to Dataran Merdeka to join the crowd waiting there.
About 350 protesters are now gathered, chanting "Free Anwar", "Kita Lawan" and singing 'Buruh Tani', an Indonesian song.
Placards with pictures of murdered Mongolian Altantuya Shaariibuu, businessman Jho Low, and Prime Minister Najib Razak's daughter Nooryana Najiwa are held by the protestors.
The protestors also play drums to boost the morale.
4.10pm: Near Dataran Merdeka - Protestors from Dataran Merdeka and Masjid Jamek have converged and numbers have swelled to 250.
4.05pm: Sogo - The PAS group has arrived at the convergence point, meeting up with about a dozen more protesters already here.
Also present are about 200 shoppers who are hanging out outside Sogo.
"We are here again to fight the tyranny of Umno!" Khalid Samad tells the crowd, getting some cheers.
4pm: Masjid Jamek - Rally-goers have started marching, led by Jingga 13 coordinator Fariz Musa.
Protesters chant " Reformasi ", " Hidup rakyat " and " Bebas Anwar ".
Fariz also chants, " Tangkap Najib and Rosmah" as well as "Tolak GST".
It is unclear whether the blare of car horns heard are in support of the rally or due to the growing traffic jam.
3.55pm: PAS HQ - PAS central committee member Dzulkefly Ahmad confirms that Mat Sabu is having his statement taken at Dang Wangi.
"I have been assured that he will not be remanded, and will be released at 4 or 5pm," he says.
The 20 protesters are now quietly marching towards Sogo, led by Shah Alam MP Khalid Samad, and PAS Muslimat committee member Aiman Athirah Al Jundi.
3.40pm: Masjid Jamek - Around 50 supporters, most clad in black shirts, are seen gathering next to the Masjid Jamek LRT station.
Most are just chit chatting, and seem to await further instructions on whether to start marching or otherwise.
3.35pm: PAS HQ - It is very quiet and hot at Jalan Raja Laut, with just four Kita Lawan protesters spotted thus far.
A PAS headquarters staffer tells a dozen waiting journalists that most of those supposed to gather there have converged at the Dang Wangi district police headquarters instead.
They are reportedly waiting for PAS deputy president Mohamad Sabu to be released there before marching to Sogo.
3.30pm: Up to 5,000 Kita Lawan supporters are expected to flood downtown Kuala Lumpur today to 'celebrate' the wedding of Prime Minister Najib Abdul Razak's daughter.
The entourage will be gathering at Dataran Merdeka, Masjid Jamek, and the PAS headquarters in Jalan Raja Laut, and converge at Sogo before heading towards the Kuala Lumpur Convention Centre (KLCC) at 4pm.
The 'festivities' are part of the demand for the release of Anwar Ibrahim as well as other related issues, such as the ouster of Najib and IGP Khalid Abu Bakar and the postponement of the Goods and Services Tax (GST) slated for April 1.
The inspector-general of police (IGP) has threatened to arrest any participants in today's rally, and police have already detained at least five of the alleged movement's leaders ahead of the protest.
Among them are PAS deputy president Mohamad Sabu, PKR vice-presidents Rafizi Ramli (Pandan MP) and Tian Chua (Batu MP), Teja assemblyperson Chang Lih Kang and social activist Hishamuddin Rais - all of whom are currently being detained by the police.
With police cracking down, it remains to be seen if the day will end with protesters singing "Kita lawan sampai menang" (We'll fight till we win) or the cops chanting, "Kita tahan sampai habis" (We'll detain all of you).
Reporting by Adrian Wong, Alyaa Azhar, Zikri Kamarulzaman, and Chai Jian Mei.