A quarter of a million people took to the streets in some 200 demonstrations around the country on Thursday, in a test of strength between youth and the conservative government of 73-year-old President Jacques Chirac.

Most of the violence - and the arrests - were around the Sorbonne university in Paris, where police fired rubber pellets and tear gas at youths who pelted them with stones and set cars on fire. Forty-six police and riot officers were injured, LCI television reported.

In Paris, 187 people were detained, city police chief Pierre Mutz said on RTL radio on Friday, blaming the violence on fringe groups of radicals and anarchists - and a few petty criminals who broke into a jewelry store in the melee.

Many trade unionists and students oppose the new youth employment law because it allows new workers under the age of 26 to be dismissed within a two-year trial period.

French Prime Minister Dominique de Villepin, the architect of the law, said he was open to dialogue and would meet university presidents to seek solutions.

But he refused to withdraw the law, which he said is essential in combating youth unemployment.

CNN/BBC