French President Francois Hollande is holding an emergency meeting with senior officials after a knife-wielding attacker killed a senior police officer and his female companion.

Prime Minister Manuel Valls, Interior Minister Bernard Cazeneuve and Justice Minister Jean-Jacques Urvoas gathered in the presidential office early Tuesday.

Anti-terrorism prosecutors are in charge of the investigation. The Islamic State's Amaq news agency cited an unnamed "source" as saying an IS fighter carried out the attack, but the extremist jihadist group has not officially claimed responsibility.

The off-duty police commander and his companion were attacked Monday night in Magnanville, about 35 miles (55 kilometers) west of Paris. The police couple's 3-year-old son was unharmed.

Following the meeting with Hollande, Cazeneuve will go to the two suburban police stations where the two police officers worked.