KUALA LUMPUR, July 9 (Xinhua) -- Police fired rounds of tear gas and water cannon to disperse thousands of activists of the Coalition for Clean and Fair Elections (Bersih) who took to the streets illegally to demand for an electoral reform in the center of the country's capital city of Kuala Lumpur on Saturday morning.
The number of demonstrators have reached more than 10,000, chanting slogans wearing the symbolic yellow shirts in front of the Petronas twin towers.
Many were injured during the stand-off.
Unofficial police report revealed 672 demonstrators were arrested, including the organizers of the rally.
Malaysia's opposition leader, Anwar Ibrahim who held a press conference Saturday morning condemning the police action at the rally was also arrested.
He was injured during the arrest.
Elsewhere in the city, members of a Malay rights group under the United Malays National Organization (Umno) - Malaysia's biggest political party and a member of the ruling coalition Barisan Nasional held a counter rally against Bersih to defend the country's electoral system.
The head of the movement was also arrested.
Local police have strengthened security checks inside Kuala Lumpur by blocking many major roads heading to the city center starting from Friday night, dispatching more police forces in the city and using helicopters to monitoring the situation.
Malaysian Home Minister Hishammuddin Hussein said on Friday that Bersih and its opponents like Umno Youth were only allowed to rally in stadium outside Kuala Lumpur and any actions inside the capital city was illegal.
Bersih, a non-government organization, vowed to launch street demonstration on July 9 advocating for a clean and fair election in the next general election, which is expected to start within this year.
Their demands include introducing automatic voter registration, reforms to postal voting and the use of indelible ink.
The organization held a similar rally with a crowd of an estimated of between 10,000 to 40,000 people in 2007 that dealt a major blow to the ruling coalition, who lost five states to the opposition during the 2008 election.