Paris, Jun 20 (IANS): Four family members of a man who was killed when his car exploded after he rammed it into a French police van on the Champs-Elysees here have been arrested, judiciary sources said on Tuesday.

The suspect's former wife, brother and sister-in-law and his father were arrested on Monday night during a search at the man's residence in Le Plessis-Pate on the southern outskirts of Paris, the sources told Efe news.

The suspect, who died in the incident, was a French national who had exhibited signs of Islamic extremism, though security services had not found sufficient evidence to justify his arrest.

The incident took place at 4 p.m. (local time) on Monday, when the assailant drove his car into a police van that was travelling in the heart of the French capital.

The car exploded and the suspect was then pulled out of it.

Various weapons, including gas cylinders, a Kalashnikov assault rifle and knives were found in the vehicle.

On April 20, a police officer was killed on the Champs-Elysees in a shooting carried out by a man who had sworn loyalty to the Islamic State terror organisation.

France remains under a state of emergency following several recent terror attacks.