Malaysian police have fired tear gas and water cannons at more than 15,000 demonstrators who took to the streets to protest against controversial internal security laws.
In chaotic scenes in the capital Kuala Lumpur, 5000 police including riot squads arrested scores of protesters as they gathered at rallying points across the city, including two mosques and a shopping complex.
At least 75 rounds of tear gas were fired and water cannons were unleashed at the Sogo shopping complex where the main crowd of some 10,000 people had gathered, intending to march on the royal palace.
The prime minister, Najib Razak, denounced the protests, saying he'd already agreed to review the controversial Internal Security Act - a decades-old law allowing detention without trial.
The legislation, a hangover from colonial days, has been used against Government opponents as well as suspected terrorists.
Deputy police chief Ismail Omar insisted the police action was not heavy-handed.
"We just wanted to disperse them, so we used water cannon and tear gas to do that," he said.
He said 175 people were arrested.
Among the detained were top opposition figures including R Sivarasa, vice-president of opposition leader Anwar Ibrahim's party.
Organisers said they wanted to present a 10-point memo to the king including demands for the abolition of the Internal Security Act, the closure of a camp where detainees are held, and an inquiry into all deaths in police custody.