Policemen stand guard near the site of the killing of a police officer in Magnanville in suburban Paris, France, on June 14, 2016. [Photo/Xinhua]

PARIS -- French President Francois Hollande on Tuesday called the killing of a senior police officer and his partner by a man who pledged allegiance to the Islamic State (IS) an "incontestably terrorist act."

French Interior Minister Bernard Cazeneuve also said earlier Tuesday that the killing was "an abject terrorist act."

"An abject terrorist act was committed yesterday in Magnanville," Cazeneuve told reporters after an emergency security meeting with President Hollande.

The minister said that 100 suspects have been arrested since January, reiterating the government's full mobilization to combat terrorism.

France has raised its terror alert after twin suicide bombings and shootings killed 130 people in November 2015.

Late on Monday, a 25-year-old man stabbed the senior police officer to death outside his home in Magnanville in suburban Paris, before hiding inside the house and taking the officer's partner and three-year-old son as hostages.

After failed negotiations to surrender, the police shot dead the assailant, who had also killed the woman. The boy was unharmed, the interior ministry said.

French intelligence services has identified the man as Larossi Abballa, a 25-year-old man who had been sentenced to three years in jail in 2013 for helping extremist militants to go to Pakistan.

An Islamic State-linked news agency report claimed that the attack was carried out by one of its fighters.