The southern French city of Nice was in mourning on Friday for the three people stabbed to death in a suspected jihadist attack at a church.
A makeshift memorial has been set up outside the Notre-Dame basilica, where people have placed flowers and lit candles for the victims.
French President Emmanuel Macron said Thursday’s stabbings were an “Islamist terrorist attack”.
He is to hold an emergency meeting with senior ministers on Friday.
Meanwhile, security has been stepped up at places of worship and schools across France following two similar attacks within two weeks. Earlier this month a teacher was beheaded in a Paris suburb after showing controversial cartoons of the Prophet Muhammad to some of his pupils.
Mr Macron’s subsequent defence of the right to publish the cartoons has stoked anger in several Muslim-majority countries.
Following the latest attack, police shot and wounded the suspected knifeman, identified as a 21-year-old Tunisian who had only recently arrived in Europe. He is said to be in a critical condition in hospital.