The operation to dislodge foreign intruders from Kg Tanduo, where more than 100 gunmen have holed up for three weeks, began at 7am today. The following is Malaysiakini's LIVE reports.
4.32pm: According to Utusan Malaysia, which quoted military sources, about 20 bodies of the Philippine intruders have been recovered. The mop-up operation continues hours after today's attack on Kampung Tanduo.
However, inspector-general of police Ismail Omar said he is still not able to confirm the number of casualties.
2.15pm: Semporna remains calm although most shops and all schools remain closed. There is no rush to stock up on food or petrol, despite a report that the police have placed the town on 'alert'.
2.12pm: The Star quotes Mohd Nazri Abdul Aziz, the minister in the PM's Department, as saying that the Lahad Datu incident is an intrusion into Malaysia's sovereignty, not a war.
"Because it is an intrusion, the situation is better dealt by the police," he says.
He also says the Sulu gunmen 'would definitely be charged with murder".
2.05pm: The US Embassy in Kuala Lumpur has issued an advisory against travel to the coastal region extending from the eastern most tip of Sabah south to the border with Indonesia. This area includes the towns of Lahad Datu, Kunak, Semporna, and Tawau.
It says local authorities have restricted movement in and around Lahad Datu in particular, and reminds US citizens to carry their passport with them at all times when in Malaysia.
Those residing in or visiting eastern Sabah should obey any evacuation and curfew orders announced by Malaysian officials, it says, adding that the embassy is not aware of specific threats to US citizens in Malaysia at this time.
Earlier today, Tourism Minister Ng Yen Yen reiterated at a press conference that Sabah is not affected by the incident in Lahad Datu, and that army officers are continuing to guard islands like Sipadan.
1.42pm: ABS-CBN reports that the Philippines is asking the Malaysian authorities to help provide a safe exit from Sabah for Filipino women and non-combatants.
Philippine Foreign Affairs Secretary Albert del Rosario (right) requests that "a corridor be made available for non-combatants and women in the area so that they will be allowed to leave the violence going on there".
Del Rosario also asks the Department of Foreign Affairs in Manila to deliver a note verbale to the Malaysian ambassador to the Philippines reiterating the appeal.
Malaysian Foreign Affairs Minister Anifah Aman says he will relay the request to Defence Minister Ahmad Zamid Hamidi.
1.30pm: Home Minister Hishammuddin Hussein and Defence Minister Zahid Hamidi arrive at the Felda Sahabat Residence by helicopter. They have been ushered into a room for briefing.
1.15pm: Information Department officials are distributing bright yellow vests tagged 'media' to journalists at the media centre.
"This is a request by the police, so we are complying. It'll make it easier to identify media personnel," explains an officer.
1.08pm: The Star tweets: Following the Tanduo operations, Semporna has been put on alert.
1.07pm: ABS-CBN reports that, at a press conference in Manila, Philippine Foreign Affairs Secretary Albert F del Rosario has remarked: "The fate of the people in Lahad Datu depend on those who continue to make a defiant stand."
1pm: In another posting at 12.43pm, the Philippine Daily Inquirer reports that Azzimuddie, who is leading Sulu gunmen in Lahad Datu, has told the Sulu sultanate spokesperson Abraham Idjirani that "we're relaxing here".
Idjirani (right) says Azzimuddie called him "two minutes ago" to inform that there were no casualties among the Sulu followers in the bombing runs by Malaysian jets.
He adds that it was "divine intervention" that no one from the royal army was hit. According to Azzimuddie, the bombs had hit Malaysian police and military positions instead.
A report filed earlier by the Manila Bulletin claims that the Moro National Liberation Front (MNLF) is joining the fray in Sabah.
The report says the MNLF's Malaysian-trained commanders will help the Sulu gunmen. It quotes former chief propagandist Hadji Acmad Bayam claims that the MNLF has a huge cache of weapons hidden deep in Sabah after their training there.
Malaysia denies the claim, saying there is no evidence to support it.
12.50pm: At the media centre in Bandar Sahabat, National Security Council secretary Mohamed Thajudeen Abdul Wahab said food had been prepared for displaced villagers.
"They have been placed in a hall nearby and we are assisting them. There is no food or water problem," he says.
12.44pm: The Philippine Inquirer posted a report at 12.27pm claiming that the 'Royal Sulu Army' in Lahad Datu will not surrender despite the offensive by Malaysian security forces.
The daily reported that Sulu sultanate spokesperson Abraham Idjirani told a radio station that the group will continue to fight and make their last stand there.
Bombs dropped by Malaysian jets struck the area but did not hit the Sulu gunmen, Idjirani said quoting Azzimuddie Kiram who is leading the group.
InterAksyon.com had posted a similar report at 10.46am.
"No. No surrender," said Idjirani, adding that Azzimuddie had told him during their last phone conversation that they were willing to fight until the end.
However it was not stated what time the phone call was made.
"He said, ‘If this is the last stand we do, let it be. But as a guerilla fighter now, we will find our way to sneak out from all dangers in order to survive'," Idjirani said.
"It only means they are afraid of us... if they were really brave, they would not use such a huge force to avoid being accused of overkill. They are showing the world that what they are doing is overkill."
11.54am: Police chief Ismail Omar says in a press statement that the joint operation between the police and military is still facing resistance. The enemies have fired several shots at the Malaysian security forces.
11.50pm: An ABN-CBS journalist uploaded a photo on Twitter of protesters setting alight an image of Prime Minister Najib Abdul Razak shaking hands with Philippine President Benigno Aquino, with the Malaysian flag in the background, outside the Malaysian embassy in Philippines.
11.45am: The situation in Bandar Cenderawasih, about 30km from the battleground, remains calm but troops have been stationed around the town to guard shops which are open for business.
Two military choppers have landed on the field of the local college.
An officer in charge informs Malaysiakini that instructions have been issued for all media personnel to remain in the media centre at nearby Felda Sahabat.
11.35am: The Star quotes police sources as saying that the Sulu gunmen in Kampung Tanduo have been "totally defeated". There are no casualties among the Malaysian security forces.
9.41am: Philippine radio station dzBB reports that Sulu sultanate spokesperson Abraham Idjarani says Azzimuddie Kiram has confirmed the launch of the assault and that a jet fighter had allegedly dropped at least two bombs.
However, Idjirani claims the bombs had hit Malaysian positions and not that of Azzimuddie's group.
The radio station also says the battle came 107 years to the day when the 1906 Battle of Bud Dajo in Sulu began.
The battle, in which some 1,000 Tausug, including women and children, were killed by American soldiers is also called the 'Massacre of Bud Dajo'.
9.37am: According to a military source, the operation involved fighter jets, artillery as well as foot soldiers moving in for the mop-up operations.
9.15am: In Lahad Datu town, about 120km from the battleground, preparations are being made at the main hospital to receive casualties.
9.11am: It is learnt that seven army battalions are deployed the area to reinforce police force.
8.54am: A Felda official arrived and told Kampung Sungai Merah village chief Rauf Bani to make a head count of his villagers and register them.
The entire group, numbering at around 300 then made their way into an oil palm road away from the conflict site.
8.45am: Fleeing villagers from Kampung Sungai Merah, about 2km from the gun battle, are seen squeezed onto lorries, with close to 50 of them on each vehicle leaving the area.
Village chief Rauf Bani says they attempted to flee to nearby Kampung Embara Budi but they were turned away.
"The guards say they wouldn't let us in so we came here," he says.
They are parked on the main road leading away from Kampung Tanduo where the battle is taking place.
8.34am: Home Minister Hishammuddin Hussein posts a photo of him briefing Prime Minister Najib Abdul Razak on the ground situation in his Twitter account.
8.28am: Prime Minister Najib Abdul Razak announces that the security forces have launched an operation to apprehend the armed
intruders at Kg Tanduo at 7am today.
“As a peace-loving Muslim country that upholds the resolution of conflicts through negotiation, our efforts to avoid bloodshed were unsuccessful. Instead, our security forces were attacked and slain, while Malaysians especially those in Sabah fear for their safety.
“The government must take appropriate action to safeguard the dignity and sovereignty of the nation as demanded by the rakyat,” he says.
"The police held meetings and negotiations in the hope that the intruders would agree to leave peacefully without the need to take any serious legal action.
"As the issue of the intrusion prolonged, it was evident to the authorities that the intruders had no intention of withdrawing from Sabah," he adds.
Philippine President Benigno Aquino is reported to have warned the intruders, who are followers of the Sulu sultan: “You will not succeed.”
A total of 26 people, including eight Malaysian police officers, have been killed in clashes with the intruders over the past week.
The group in Sabah is being led by the sultan's brother, Azzimuddie Kiram, who has refused to surrender.
8.24am: Explosions are heard about 7.30am, near Kampung Tanduo which is occupied by a group of foreign intruders. Villagers have started fleeing.
"They've starting bombing the area. We saw jet fighters in the sky, they bombed the place four times," says villager Nasir Asrama, 38.
The villagers are from Kampung Sungai Merah, a neighbouring coastal village of Kampung Tanduo where some 100 heavily armed intruders from the Philippines have holed up.
Kampung Tanduo sits between Tanjung Labian and Kampung Sungai Merah which are 5km and 2km apart respectively.