PARIS (REUTERS) - A 47-year-old man has been taken into custody on suspicion of having been in contact with the perpetrator of Thursday's (Oct 29) deadly knife attack in Nice, a judicial source said.

On Thursday, a knife-wielding attacker shouting "Allahu Akbar" (God is Greatest) beheaded a woman and killed two other people in a church in the French city before being shot by police and taken away.

The source said the 47-year-old suspected of having been in contact with the attacker had been detained late on Thursday evening, confirming an earlier report on BFM TV.

France's chief anti-terrorist prosecutor Jean-Francois Ricard said the man suspected of carrying out the attack was a Tunisian, born in 1999, who had arrived in Europe on Sept 20 in Lampedusa, the Italian island off Tunisia that is a major landing point for migrants from Africa.

A Tunisian security source and a French police source named the suspected attacker as Brahim Aouissaoui.

Ricard said the suspected attacker had entered the city by train early on Thursday morning.

The French Interior minister said on Friday (Oct 30) that France is engaged in a war against Islamist ideology and more militant attacks on French soil are likely.

"We are in a war against an enemy that is both inside and outside," Gerald Damarnin told RTL radio. "We need to understand that there have been and there will be other events such as these terrible attacks."

The Nice attack occurred just under two weeks after a school teacher in a Paris suburb was beheaded by an 18-year-old attacker who was apparently incensed by the teacher showing a cartoon of the Prophet Mohammad in class.