|Many opposition activists were held for participating in Friday's rally, declared illegal by the government [EPA]|
Malaysia cracks down on protesters
Police in Malaysia have fired tear gas and arrested hundreds of protesters in the biggest opposition-backed rally in years.
More than 20,000 demonstrators massed across Malaysia's capital Kuala Lumpur on Saturday, demanding electoral reforms, activists said.
The federal police force said that it detained 644 people in a clampdown called Operation Erase Bersih, referring to the Bersih coalition, the group organising the rally.
Those arrested included several senior opposition officials.
"The public is reminded not to be involved in any demonstration," the federal police force said in a statement and warned of "stern action ... against those who disobey".
Witnesses said riot police armed with batons charged at some protesters and dragged them into trucks.
Numerous restaurants and stores were closed because of the transportation disruptions and fears of violence.
The government had declared the demonstration illegal, and police had sealed off parts of the capital in advance.
Strict security measures
Authorities took extraordinary security measures to deter the rally by closing train stations and deploying lorries mounted with water cannons near the Independence Stadium in a suburb of Kuala Lumpur, where activists sought to gather.
Nevertheless, thousands tried to reach the stadium from various parts of the capital, chanting "Long live the people" and carrying yellow balloons and flowers as they marched.
Police fired numerous rounds of tear gas and chemical-laced water in repeated attempts to disperse the crowds, causing demonstrators to scatter into nearby buildings.
Helicopters flew overhead as a brief downpour failed to deter the protesters.
Anwar Ibrahim, the opposition leader, said on Twitter that he sustained a "minor injury" when his group was hit by tear gas.
Government officials accuse Anwar's three-party alliance of endorsing the rally to cause chaos on the streets and undermine the National Front, the federal ruling coalition.
The rally organisers called for reforms following accusations that the Malaysian election commission is biased towards the ruling coalition, which has been in power since independence from Britain in 1957. The commission denies the charge.
The government insists the current electoral policies are evenhanded.
Over the past two weeks, more than 200 other activists have been arrested nationwide for trying to promote the rally.
Earlier, speaking to Al Jazeera over phone from Kuala Lumpur on Saturday, Edmund Bon, a human-rights lawyer, said:
"It's an extraordinary clampdown on the whole [city] and we are not allowed to go anywhere.
"People are getting arrested on the streets and about 250 to 300 people have been arrested so far in connection with the rally.”
The activists' demands include an overhaul of voter registration lists, tougher measures to curb fraud and fairer opportunities for opposition politicians to campaign in government-linked media.
A general election is not due until 2013 but Najib Razak, the prime minister, has not ruled out early polls, after economic growth accelerated to a 10-year high in 2010.
Major street demonstrations are rare in this Southeast Asian country, but the rise of alternative media channels and a growing opposition voice are gradually creating a more vocal Malaysian public.