Policemen use pepper sprays on protesters trying to march during a rally in central Seoul on Nov 7, 2010. More than 20,000 workers from the Korean Confederation of Trade Unions (KCTU) and students rallied in central Seoul on Sunday to oppose the G20 Seoul Summit as well as to demand the guarantee of workers' basic human rights and abolition of discrimination against temporary workers. The G20 Summit will be held in Seoul from Nov 11 to 12. [Photo/Agencies]

SEOUL - Thousands of people chanted anti-globalization slogans in South Korea's capital Sunday to protest this week's Group of 20 summit. Part of the crowd attempted to march down nearby streets but were stopped by riot police, who fired pepper spray.

The protesters sang, danced and waved signs reading "We oppose the G20" at a large plaza near Seoul City Hall. South Korea is hosting a gathering of leaders from the G20 advanced and developing economies on Thursday and Friday.

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Some protesters danced and played traditional Korean drums, while about 9,000 riot police and many police buses encircled the rally site to keep order. Police said about 20,000 people took part in the rally.

The rally was initially peaceful, but some protesters engaged in minor scuffles with riot police who tried to prevent them from marching through downtown streets. Riot police fired pepper spray at some protesters at the front of the crowd, forcing them back.

The protesters oppose globalization and say the G20 is not focusing on creating jobs or protecting social programs.

Labor activist Lee Chang-geun accused the G20 of failing to formulate meaningful measures to curb speculative financial capital and of pushing cuts in public spending on social welfare.

Activists plan to stage smaller rallies every day until the summit begins Thursday, he said.

In Manila, six Filipino activists who planned to join anti-globalization rallies in Seoul said they were denied entry by South Korean immigration officials on Saturday and forced to return home.

"We condemn the South Korean government and we demang then the financial system to prevent a recurrence of the 2008 crisis. It held its first summit in Washington two years ago.

South Korean police and military are on heightened alert to prevent any attempt by protesters, terror groups to sabotage the summit, which will include US President Barack Obama and other leaders.