At least 40,000 police officers are being deployed across France to deal with protests triggered by the fatal police shooting of a 17-year-old driver.

The teenager, named as Nahel M, was shot at point-blank range as he refused a traffic stop and drove away.

At least 180 people have been arrested after a second night of unrest, while 170 officers were injured, France's interior minister says.

In Nanterre, where Nahel was shot, vehicles were set on fire and police fired tear gas, while people broke into the town hall and started fires outside Lille.

The police officer who shot the teenager has been placed under formal investigation for voluntary homicide.

French President Emmanuel Macron has held a crisis meeting and called the violence on the streets "unjustifiable" in appealing for calm.

Nahel came from a French-Algerian family, a neighbour told Reuters news agency. Their tally found that most of those killed by police in traffic stops since 2017 were black or Arab.