A third man has been detained for questioning in connection with the knife attack on a church in the southern French city of Nice that left three people dead, a legal source said Saturday.
The man, 33, was present during a police search late Friday at the home of a second man who was also detained for questioning as he was believed to have been in contact with the attacker, the source said.
"We are trying to clarify what his role is in all this," the source added.
The suspect in Nice, who was shot and hospitalised in a critical condition, has been identified as a 21-year-old Tunisian man who arrived in Europe a little over a month before the attack, according to French investigators.
President Emmanuel Macron has called the deadly stabbing an "Islamist terrorist attack" and announced increased surveillance of churches by France's Sentinelle military patrols, to be bolstered to 7,000 troops from 3,000.
Security at schools would also be boosted, he said.
"Quite clearly, it is France that is being attacked," the president added, vowing the country "will not give up on our values".
It occurred almost two weeks after Samuel Paty, a school teacher in a Paris suburb, was beheaded by an 18-year-old Chechen. Paty had shown his pupils such cartoons in a class on freedom of expression.
France, home to Europe's largest Muslim community and hit by a string of militant attacks in recent years, has defended the right to publish such cartoons. Macron has insisted France will not compromise on its basic freedoms of belief and expression.
(FRANCE 24 with AFP, REUTERS)