Organisers of a rally protesting the treatment of ethnic Indians in Malaysia said Friday they would proceed with their demonstration here over the weekend, though police had banned it.

Activists plan to gather thousands of people on Sunday in front of the British mission to denounce what they say is discrimination and marginalisation of Indians in Malaysia, said P. Waythamoorthy, chairman of Hindraf, the group organising the protest.

Since Thursday, police have set up roadblocks in the capital's narrow streets -- a move organisers said was aimed at preventing them from bringing in their supporters.

And on Friday, P. Uthayakumar, Hindraf's legal adviser, was arrested, said Waythamoorthy.

"This goes to show the government of Malaysia is trying to frustrate our attempts at getting justice," Waythamoorthy told AFP before he was also detained.

Suffian Sulaiman, spokesman for Kuala Lumpur police, told AFP the arrests and the roadblocks around the capital were intended to stop the protest. Police last week issued the ban order on the rally.

"These are preventive measures. This is an illegal gathering. We urge the public against participating in the rally," Suffian said.

Police have also warned that protesters may raise sensitive racial issues, which could spark clashes.

Protests are rare in Malaysia. The rally, if it happens, will be Malaysia's second street demonstration in a month. The earlier protest attracted some 40,000 people who rallied for electoral reforms.

In August, Waythamoorthy filed a lawsuit in London, seeking one million pounds (two million dollars) compensation for each of the estimated two million Malaysian Indians who were brought to the country in the 1800s as part of British imperial expansion.

Organisers of the rally planned to submit a petition to the British mission in Malaysia asking Queen Elizabeth II to appoint a Queen's Counsel to represent Malaysian Indians in the lawsuit.

Ethnic Indians account for eight percent of Malaysia's population. About 80 percent of them are working class and lack skills, money and education.

Forming 60 percent of the nation's 27 million people, ethnic Malay Muslims make up the main political group, while 26 percent are Chinese.