Rioters Mar Anti-Racist London Rally

LONDON —  Demonstrators fought running battles with riot police and pelted them with stones Saturday after Britain’s biggest anti-racist demonstration in 15 years was hijacked by violent troublemakers.

Police said the street clashes, the worst since 1990 riots over the unpopular local “poll tax,” were caused by an extremist minority. March organizers said police attracted trouble by stressing the possibility of violence.

The trouble started when 2,000 police formed a barricade across a road in Welling, southeast London, to keep more than 20,000 anti-racist protesters from reaching a bookshop that serves as the headquarters of the extreme right-wing British National Party.

Tension has been high in the rundown East End since a BNP candidate won a local government seat last month. There has been a sharp increase in attacks on blacks and Asians since the BNP opened the bookshop about 18 months ago.

As marchers tried to force a way through, masked youths threw bricks, smoke bombs and sticks at the police.

Police reported 12 officers had been hurt, one with serious neck injuries. There were 11 arrests.