Malaysian police fired tear gas and water cannon at thousands of protesters who converged on Kuala Lumpur's centre to demand electoral reforms, raising the risk of a backlash against the government in national elections expected within months.

A protester takes photos with his tablet computer as protesters march down a street during a rally in Kuala Lumpur April 28, 2012., Photo: REUTERS/Samsul Said

Protesters also battled with police at a train station nearby, throwing bottles at officers who responded by firing tear gas rounds.

Thousands of protesters who had been confronting police outside the city's historic Merdeka Square were scattered after riot police fired water cannon and then at least 10 rounds of tear gas into the crowd. The police said they had been forced to react after protesters tried to force their way through barriers and enter the square.

The violence could carry political risks for Prime Minister Najib Razak if it is seen as unjustified, possibly forcing him to delay elections that must be called by next March but which could be held as early as June. Najib's approval rating tumbled after July last year when police were accused of a heavy handed response to the last major electoral reform rally by the Bersih (Clean) group.

"They asked the crowd to disperse but did not give enough warning," said Aminah Bakri, 27, with tears streaming down her face from the tear gas exposure.

At least 25,000 protesters had converged on the city's historic Merdeka (Independence) square, where they were met by barbed wire and hundreds of police with water cannon trucks standing ready.

Some media sites put the number of protesters as high as 50,000, making it the biggest since "Reformasi" (Reform) demonstrations in 1998 against then Prime Minister Mahathir Mohamad.

"The people have surprised us. We all want change today," said Ambiga Sreenevasan, co-chairperson of the Bersih (Clean) movement that is leading the protest.

The protest is a delicate challenge for Najib, possibly affecting the timing of elections that he is preparing to call as early as June.

A violent response by police risks alienating middle-class voters and handing the advantage to the opposition in what is shaping up as the closest election in Malaysia's history, possibly forcing Najib to delay the poll date.

But Najib must be mindful of conservatives in his party who are wary that his moves to relax tough security laws and push limited election reforms could threaten their 55-year hold on power.

Supporters of Bersih were barred by a court order from holding their mass "sit-down" protest in the symbolically important Merdeka Square, but they went ahead with plans to march as close as possible to the site.

Source: Reuters