The attack started around 9pm local time with the fatal stabbing of the plain clothed officer, identified by French media as Jean-Baptiste Salvaing, 42, near his Magnanville home, AFP reported.

The assailant, reportedly a neighbor, stabbed the police officer nine times in front of the house before taking his wife and son hostage, Le Parisian reported. The outlet said the victim was a deputy chief of the judicial police at the Les Mureaux police station.

Neighbors who called police claimed they heard the man chanting Islamist slogans, Reuters France reported.

Elite Raid police units arrived at about 21.30 p.m. and cordoned off the area. The attempt to enter into negotiations with the man failed. The motives of the attack have not been immediately clear.