Forty people were arrested in Seoul when protests over government labour policies and the handling of last year's ferry disaster spiralled into violence.

Thousands of demonstrators, many of them carrying banners and wearing yellow jackets, the colour identified with supporters of the families of the ferry disaster victims, occupied several city centre streets.They clashed with police officers, who created tight perimeters with their buses and aggressively blocked the marchers from reaching the presidential Blue House. South Korean labour groups have been denouncing a series of government policies they believe will reduce wages, job security and retirement benefits for state employees.