SEOUL - TENS of thousands of South Korean activists protested on Sunday against the Group of 20 summit to be held in Seoul this week, with police on high alert for violence in the capital's streets.

Labour campaigners and other activists chanted slogans and songs at Seoul Plaza outside the city hall, surrounded by thousands of riot police. 'We will continue the struggle to raise the minimum wage, solve the youth unemployment issue... We will never allow only 20 elite countries to decide the whole world's future,' the organisers chanted on the stage.

Police said about 20,000 people took part in the protest, while the organisers - who included the Korea Confederation of Trade Unions, a major workers' rights group - estimated the number at 40,000.

Some wore red vests with a slogan reading: 'Against the G20 that hampers labour rights and creates unstable jobs'. Others held up mock traffic signs saying 'Stop G20'. Campaigners distributed leaflets urging people to 'rise up against neoliberalism and globalisation'.

There was no violence in the first two hours after the rally began at 3pm (0600 GMT, 2pm S'pore time) but police expected clashes, a city police spokesman told AFP. 'Organisers are saying they will march towards the city centre against police warnings. We are expecting some clashes to take place soon,' he said.

More than 8,000 police were deployed around the city centre, he added.

Thousands rally in SKorea