SAN SEBASTIAN (AFP) -- Riot police clashed Sunday with pro-independence Basque demonstrators and detained four people in the northern Spanish city of San Sebastian, a spokesman for the Basque government said.

Masked demonstrators threw stones and bottles at the police, after authorities moved to disperse hundreds of people gathered in the city's center for the protest which was banned by the Basque government.
The demonstration was called by several left-wing Basque nationalist movements to demand an amnesty for jailed members of the armed group ETA, which has killed over 800 people in its 40-year campaign for an independent Basque homeland.
ETA declared a ""permanent ceasefire"" in March 2006 which it called off just 15 months later, citing lack of progress in tentative peace talks with the socialist government of Prime Minister Jose Luis Rodriguez Zapatero.
It has since killed four people and carried out a series of bombings, mostly in the northeastern Basque region.
Police have detained dozens of suspected members and supporters of ETA since the end of the ceasefire, while Zapatero has repeatedly ruled out any further talks with the group.
ETA, whose initials stand for Euskadi ta Askatasuna, or Basque Homeland and Freedom in the Basque language, is considered a terrorist organization by the European Union and the United States.