Police have shot dead a man who killed a policeman and his wife in a suburban area northwest of Paris. Authorities have launched an anti-terror investigation into the killings amid reports of a potential "IS" link.

Police sources said the suspect attacked the 42-year-old police commander with a knife in front of his home in Magnanville, about 55 kilometers (32 miles) from the French capital late Monday.

The assailant then barricaded himself inside the house and took the policeman's wife and son hostage.

Elite police commandos surrounded the property and forced their way inside after attempting for a number of hours to negotiate with the man. The suspect was shot dead during the operation.

Interior Ministry Spokesman Pierre-Henry Brandet told reporters that police had managed to rescue a three-year-old boy from the home, but that the policeman and his partner had been found dead.

"The investigation is beginning. We have no indication - serious (indication) - on the motivation behind this act," French prosecutor Vincent Lesclous said, adding that the assailant's identity was unknown.

The slain policeman worked in nearby Les Mureaux, while his partner was a civil servant with the interior ministry.

Possible 'IS' link

The Amaq news agency linked to "Islamic State" (IS) cited an unnamed "source" as saying the man was an IS militant, however the terror group has not officially claimed responsibility for the killings.

If it is confirmed that IS is behind the murders, it would be the first militant strike in France since the government imposed a state of emergency after the November Paris attacks that killed 130 people.

French President Francois Hollande condemned the attack as an "odious act," and said an emergency meeting would be held at his Elysee 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.

(DW)