French police staged protests in Paris and other cities for a fifth night on Friday, in a movement showing no sign of abating despite President Francois Hollande's government attempts to defuse tensions just months before a presidential election.

Police say they are no longer sufficiently equipped even to defend themselves and have staged five nights of unauthorized demonstrations. Some 3,000 of them took to the streets on Thursday night, they said.

Hundreds of officers protested on Friday night in front of Notre Dame cathedral in central Paris, just opposite the central police headquarters. Other protests took place in Calais, Lille, Toulon and other cities.

Speaking from a European Council meeting in Brussels, Hollande said he would meet police representatives at his office early next week to hear their grievances.

Police discontent was fueled by an incident in a town near Paris earlier this month, where a gang petrol-bombed four police officers in a patrol car.

The car was stationed at a crossroads notorious for smash-and-grab robberies on motorists. Police say the gang tried to prevent the officers from getting out of the burning vehicle. Two of the four were seriously injured and one suffered life-threatening burns.

Unions say a surge in criminal gang activity and militant attacks has put extra strains on police.

Thousands of police and soldiers have been deployed to guard airports, train stations and other sites in response to Islamist attacks that have killed more than 230 people in France in the past two years.