A senior police officer and his wife were murdered outside of Paris Monday night by a man who reportedly claimed allegiance to the ISIS terror group.
The couple's three-year-old son was found safe after commandos stormed the home in Magnanville, about 35 miles west of the French capital.
The off-duty commander was attacked and stabbed nine times in the abdomen outside his home, interior minister spokesman Pierre-Henry Brandet told reporters at the scene. The attacker then retreated indoors and held the officer's wife, a fellow police worker, and their son hostage, setting up a roughly three-hour standoff.
"The toll is a heavy one," Brandet told reporters, his voice heavy with emotion.
Officials said the attacker was killed by police when they stormed the residence, but it was unclear how his wife was killed. French prosecutor Vincent Lesclous — who said he knew the murdered police commander — told reporters that the boy was found "shocked but unharmed." He said the assailant's identity was unknown.
French media, some of them citing uamed neighbors, reported that the attacker was heard shouting "Allahu Akbar" — Arabic for "God is Great" — during the attack.
The Islamic State's Amaq news agency cited an uamed "source" as saying an ISIS fighter carried out the attack, but the extremist jihadist group has not officially claimed responsibility.
French officials said anti-terrorism prosecutors were investigating the attack due to the target, the method behind the attack, and what the attacker said to police during the ensuing standoff. The office did not elaborate.
France, like other countries in Europe, has seen a series of stabbings aimed at police officers or soldiers and carried out by Muslim radicals. IS has encouraged its supporters to stage such attacks.
The country's president, Francois Hollande condemned what he described as an "odious act," saying that he would hold a meeting at his Elysee Palace office on Tuesday.
"Light will be shed on the circumstances of this abominable drama whose investigation, under the authority of justice, will determine the exact nature," Hollande said in a statement.
France has been under a state of emergency since a series of co-ordinated shootings and bombings killed 130 people in Paris this past November. The country is currently hosting the European soccer championship, and stadiums and other public places are under tight security.
The Associated Press contributed to this report.