Seven police officers were slightly injured and six youths were arrested in a neighbourhood of Seine-Saint-Denis in confrontations that started at around 2030 GMT on Monday, a security official from the suburb said on Tuesday.

Seine-Saint-Denis is to the north of the French capital.

The youths began burning cars in reaction to a police operation in which a young man was arrested several hours earlier. Officials said they did not yet know how many cars had been burnt.

There were also incidents in the neighbouring area of Clichy-Sous-Bois, where last year's riots began after two boys died while they were apparently fleeing police.

In the three weeks of rioting that followed around France, youths clashed with police in poor suburbs which are home to large immigrant populations.

Some 9,000 cars and several schools were set ablaze and the government was forced to use emergency powers to quell the unrest that was the worst France had seen in nearly 40 years.

Immigrant complaints

The rioters, many of whom were of African or Arab in origin, complained of discrimination, high unemployment and lack of opportunities.

Last year, 9000 cars and several
schools were burnt by rioters

Nicolas Sarkozy, the interior minister, has said the riots showed that the immigration system was not working.

He proposed changes that have been criticised by opposition parties and immigrant groups.

The law, which is due to be debated in the senate next month, aims to keep unskilled immigrants out and improve integration with language tests.

Dominique de Villepin, the French prime minister, responded to the violence by proposing a law earlier this year that he said would help reduce youth unemployment in poor suburbs.

But students and opposition parties objected and organised mass protests that prompted Villepin to withdraw the project last month and raised questions about his future in the run-up to the presidential election next year.