Picture used for illustrative purposes only.

The three were part of a group of five men in their 20s who left a nightclub shortly after 5am (0300 GMT) and were driving away when their car was attacked by unknown men with Kalashnikov rifles, they said.

The two survivors of the attack — which took place in a residential neighbourhood of Marseille, France's second-biggest city — were unharmed and fled the scene, as did the shooters.

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Police found a burning car nearby, but would not confirm immediately whether it was the gunmen's getaway car.

The torched car would, however, be consistent with previous drug-related killings in Marseille where the perpetrators often set their vehicles ablaze to destroy any evidence.

Early indications were that the men who were attacked lived in a council estate with a high incidence of drug trafficking and were known to police, according to a source close to the investigation.

Regional prefect Frederique Camilleri told reporters at the scene that "the entire police force has been mobilised to find the perpetrators of these despicable crimes and to dismantle the networks of the traffickers behind this violence".

This weekend alone, police had arrested five people for possession of firearms linked to the drugs trade, and seized three Kalashnikov assault rifles, a submachine gun and a handgun, she said.

Agence France-Presse