PARIS • Violence spread in Paris' northern suburbs and a dozen people were arrested, French police said yesterday, amid accusations that officers had raped and beaten a man they were detaining.

Dozens of vehicles and a nursery school were set on fire by youths during stand-offs with police, in an area of Paris where riots in 2005 drew global attention to the stark contrast between wealthy Paris and the suburbs that surround it. As well as damaging the nursery school and a car sales outlet, youths also used a shopping trolley full of petrol bombs, police said.

The trouble began in Aulnay- sous-Bois last Thursday, when four police officers were accused of using excessive force while arresting a 22-year-old man, including raping him with a baton. "For the moment, we're talking of very violent but isolated stand-offs," said Mr Luc Poignant from the SGP police union.

While much more limited than 12 years ago, the unrest served as a reminder of the simmering tensions in neighbourhoods with higher-than-average unemployment and big immigrant population, as France prepares to elect a new president this year.

The jobless rate in Aulnay-sous- Bois is nearly twice the national average of 10 per cent. "Sadly these neighbourhoods have been turned into ghettos," said police representative Yves Lefebvre, adding that police were not sufficiently trained or equipped to deal with the problems in the sprawling suburbs where drug dealing is rife.

The four police officers have been suspended pending an inquiry; one has been placed under formal investigation for suspected rape and the other three for unnecessary violence.

The victim, a young black man, has himself called for calm, and he and his family say they trust the justice system will deal properly with the incident.

President Francois Hollande has visited the man in hospital.

Police said the skirmishes on Tuesday night were mainly in towns around Aulnay-sous-Bois, which itself was relatively calm.

The unrest is playing out against a backdrop of growing political uncertainty in France, with support growing for far-right leader Marine Le Pen and her challenger for the presidency, conservative Francois Fillon, hit by allegations that his wife had been paid by the state for a fake job.

The 2005 riots, in which 10,000 cars and 300 buildings were set on fire, prompted then Interior Minister Nicolas Sarkozy to declare a state of emergency.

Political opponents say Mr Sarkozy made matters worse when, as president from 2007 to 2012, he scrapped specialised local police teams and cut police staffing by 10,000.

REUTERS