Scores arrested in Paris Tamil protest on Sri Lanka

PARIS, April 20 (Reuters) - Around 180 people were arrested and four injured in Paris on Monday during an unauthorised protest by Tamils that turned violent, a police spokesman said.

Expatriate Tamils have been demonstrating around the world against the Sri Lankan government's conduct of the war against Tamil Tiger rebels. London has been a focus as many Tamils blame Britain, the former colonial power, for denying them a homeland.

Protesters blocked traffic at a junction in northern Paris and threw objects at three buses and police, the spokesman said, adding that four people were slightly injured, including one policeman.

Police described the gathering as an "armed crowd", a term generally used for groups carrying knives, guns or improvised weapons such as metal bars.

A larger demonstration took place in London, where thousands of Tamils blocked streets outside Britain's parliament, accusing the Sri Lankan government of disregarding civilians trapped by the fighting against the Tamil Tigers and demanding a ceasefire.

Sri Lankan government troops have encircled Tamil fighters in a small pocket in the northeast of the island. The United Nations has accused the government of shelling civilian areas and the Tigers of shooting civilians trying to flee.

The government on Monday gave the guerrillas 24 hours to surrender after several thousand civilians managed to flee the war zone. The International Crisis Group said a "humanitarian tragedy" was unfolding in the region, with around 150,000 civilians still trapped. (Reporting by Jean-Baptiste Vey; writing by Francois Murphy; editing by Tim Pearce)