PARIS (Reuters) - Gangs of French youths torched cars and bins in a showdown with police in a north Paris suburb overnight in a grim reminder of the simmering tension that sparked weeks of more serious rioting in the area a decade ago.

It was the third night of tension since four police officers were suspended pending an inquiry into accusations they had used excessive force while arresting a 22-year-old man there, including shoving a baton into his anus.

At one point in the skirmishes in Aulnay-sous-Bois late on Monday night, several police who ran out of tear gas fired real bullets into the air to scare off a crowd that had surrounded them, said police representative Luc Poignant.

“Things could have been a lot worse. We could have had eight dead police officers,” he said in defense of the law enforcement staff deployed to the area.

One of the police officers involved in the man’s arrest on Feb. 2 has been placed under formal investigation for suspected rape and three others for unnecessary violence.

President Francois Hollande visited the victim at the Aulnay hospital on Tuesday, an Elysee source said.

The riots played out against a backdrop of growing political uncertainty in France, where far-right leader Marine Le Pen leads the pack of candidates to succeed Hollande in May and conservative standard bearer Francois Fillon has been slowed by accusations he had his wife paid by the state for a fake job.

Aulnay-sous-Bois is one of several areas where riots erupted in 2005 after two teenagers who fled police in the nearby neighborhood of Clichy-sous-Bois died from accidental electrocution in a power station where they had taken cover.

That incident sparked three weeks of rioting in which 10,000 cars and 300 buildings were set on fire, prompting then interior minister Nicolas Sarkozy to declare a state of emergency and drawing worldwide attention to the contrasts between Paris and the bleak suburbs around it.

In Aulnay, where the unemployment rate of 19 percent is near double the national average, petrol bombs were thrown and police used tear gas in confrontations around a sprawl of buildings that were built in the late 1960s to house workers at a nearby car factory. That plant closed in 2013.

“This violence is incomprehensible,” Mayor Bruno Beschizza said of the incidents in Aulnay-sous-Bois, about 15 km (9 miles) northeast of central Paris.

A hospital examination of the arrested man revealed wounds to his rectum, face and head, it said.

Interior Minister Bruno Le Roux, questioned in parliament, said the arrested man was now in hospital with serious injuries but called for calm in the area.