Malaysian police used a water cannon to disperse protesters who held a candlelight vigil on Saturday against internal security laws being used to hold ethnic Indian activists without trial.
Some 300 people including women and children defied a police ban and attempted to gather at the capital's Independence Square, but were barred by about 100 police including dozens of riot police.
They held a brief vigil, lighting candles and singing rights anthems, before being dispersed by riot police, several carrying tear gas, and backed by a water cannon which was briefly turned on.
The crowd scattered into surrounding streets and were chased down by police officers but no arrests were made, said organisers, who said their cause had been energised by the latest arrests under the Internal Security Act (ISA).
Five members of the Hindu Rights Action Force, which organised a mass rally in November alleging discrimination against ethnic Indians in Malaysia, which is dominated by Muslim Malays, were last month detained under the legislation.
They can be held indefinitely without trial under the law, which dates back to the British colonial era when it was used against Communist insurgents.
"Our presence tonight is to say that this is a law which is unjust," Abolish ISA Movement chairman Syed Ibrahim told reporters, adding that Malaysians of all races and religions were represented at the vigil.
Protesters urged the government to abolish the ISA, which in modern times is more commonly used against alleged Muslim militants.
"The ISA law is no longer relevant. A crime should be proved in a court of law, instead of denying people their human rights," said H Nandakumar, a 24-year-old engineer who attended the rally.
"People are starting to realise that the government is selected by us and we don't need laws that are patronising. We can think for ourselves -- we are not children," he told AFP.
Religious and racial issues are extremely sensitive in multi-racial Malaysia, which experienced deadly race riots in 1969.
Malays make up 60 per cent of the population, with ethnic Chinese at 26 per cent and Indians at eight per cent.