Worst ever riots strike Malaysia

Defying government warnings, around 15,000 protestors were on streets in response to the call by the opposition, and later a police spokesman said 175 people had been arrested amidst chaotic scenes in downtown area of the city.

It all began in small gatherings in street corners which later swelled into a huge protest march with people intending to march to the Royal Palace to register their protest.

Crowds played cat-and-mouse with the police, disappearing into side streets at the first sign of heavy deployment only to re-emerge from different sides.

The protest caused huge traffic snarls in the city with buses going off the roads and the trains halted half-way to their destinations wary of stone pelting.

The new Prime Minister Najib Tun Razak denounced the protest saying it was unnecessary as he had already announced to review the Internal Security Act (ISA), a hangover from colonial times.

The gathering is being considered the largest since the 2007 ethnic Indian protests organised by the outlawed Hindu Rights Action Force (Hindraf). Some online sites put the number of demonstrators as high as 20,000.

People from early morning began gathering at city's main mosque, shopping malls and a railway station and started marching towards the national palace.

They chanted "Reformasi", the opposition political party's slogan for political change, and tried to submit a petition to the country's king to denounce the act.

They also called for the closures of a camp in northern Perak state where detainees are held, and an inquiry into all deaths in custody and allegations of police abuse of power.

Police backed by riot squad officers and helicopters scuffled with protestors and fired tear gas and chemical-laced water to disperse them. They also charged the protestors with batons.

"The police are really brutal," opposition leader Anwar Ibrahim told reporters at the protest. "This clearly shows (the government's) intolerance to any dissent. ... We gather here today to fight a cruel law."

Some online reports claimed that around 200 people had been arrested and 75 rounds of tear gas were fired.

Among the detained were several top political figures including R Sivarasa, vice-president of opposition leader Anwar Ibrahim's party. The sustained police offensive sent the huge crowd scattering, with many coughing and choking from the effects of the gas.

The roadblocks set up by the authorities to stop the demonstrators from entering downtown area resulted in massive traffic jams around the city and adjacent areas.

Restaurants and stores were closed in some places ahead of the planned rally.

Bernama news agency also reported Higher Education Minister Mohamed Khaled Nordin as saying that legal action would be taken against tertiary students found participating in anti or pro-ISA gatherings.

"If there are students involved in the gatherings and if they allow themselves to be victimised and used for other people's agenda, I will not protect them," he told reporters.

Defence Minister Ahmad Zahid Hamidi said it was impossible for the Internal Security Act to be abolished but felt it could be amended or its name changed to be more appropriate with current times.

He said the country needed laws like the ISA that could allow a person to be questioned before a matter or case could be taken to court, as well as needing other laws.

"Don't just look to our country only. See our neighbours or other countries. They too have laws more or less like ours or stricter. The act is meant to ensure economic and political stability so that there are no problems related to religion, race and culture and this is what the government stresses," national news agency Bernama quoted him as saying.

He noted that people should not be afraid of the ISA if they had not done anything wrong. "I speak from my experience in 1988. Although I was detained under the ISA, I accepted the situation. When I was questioned and investigated, I was of the opinion that the police did their job professionally," said Ahmad Zahid.

Under the law, authorities can detain any person without trial for an indefinite period, citing security threat. Under the same act, five prominent Hindu leaders of the outlawed Hindu Rights Action Force (Hindraf) were detained after the 2007 ethnic Indian protests.

They were released recently after Prime Minister Razak assumed office.