French Muslim part of a terrorism investigation repeatedly stabs his wife, man had links to other terrorist organizations

France confronted homegrown terrorism and possible security failings again on Tuesday after a convicted Islamist extremist who was under surveillance killed a police officer and his wife near Paris.

Isis, the Islamist group, claimed responsibility for the murders via its affiliated news agency, Amaq.

Larossi Abballa, a 25-year-old French citizen who had spent time in jail for his ties to a jihadi group, stabbed a 42-year-old police commander to death as his victim returned home on Monday evening.

The police officer’s wife, an employee of a police station in the nearby town of Mantes-la-Jolie, was also killed after Abballa barricaded himself in the couple’s home in Magnanville, north-west of Paris. Elite police forces then shot the knifeman and saved the couple’s three-year-old child.

François Hollande, French president, who convened an emergency meeting on Tuesday, called the double murder a “horrifying tragedy” that was “incontestably a terrorist act”.

Speaking at the Organisation for Economic Co-operation and Development in Paris, Mr Hollande said France was facing a terror threat “of a very large scale”.

The killings came a day after a gunman claiming to be acting in the name of Isis shot dead 49 people at a gay nightclub in Orlando, in the worst mass shooting in US history.

It also comes as France is on high alert as it hosts the Euro 2016 football tournament with the memory of the co-ordinated Islamist attacks that killed 130 people in Paris in November still fresh in people’s minds.