French security forces have said they are trying to catch the gunman suspected of attacking a Christmas market dead or alive.
The attack in Strasbourg left three people dead and wounded 13 others, including five who are in a serious condition.
More than 700 officers are involved in the manhunt for 29-year-old Cherif Chekatt, who had been flagged for extremism, government spokesman Benjamin Griveaux said. Prosecutors have opened a terror investigation into Tuesday’s attack.
A police operation later took place in the Strasbourg neighbourhood where Chekatt was last seen.
One French police official said security forces, including the elite Raid squad, were taking action based on a “supposition only” that Chekkat could be hiding in a nearby building.
The government raised the terror alert level nationwide and deployed 1,800 additional soldiers across France to help patrol streets and secure crowded events.
Mr Griveaux also called on the “yellow vest” protesters not to take to the streets, as some members of the movement have planned a fifth round of demonstrations on Saturday across France to demand tax relief.
Strasbourg was in mourning, with candles lit and flowers left at the site of the attack. The Christmas market was closed at least again on Thursday.
Pastor Philippe Eber said this is a moment “to think of those who died in this city because of violence. We also are thinking about all of those who weep for them, the families”.
Strasbourg resident Tassia Konstantinidis said “it’s important to have a period of mourning and to remember the victims”.
Italian Interior Minister Matteo Salvini said one Italian was among the wounded, in critical condition. The Europhonica radio consortium said Antonio Megalizzi, 28, was in Strasbourg to follow the session of the European Parliament when he was shot.
French authorities said that the suspect, born in Strasbourg, had run-ins with police from the age of 10 and his first conviction was at 13.
Chekatt had been convicted 27 times, mostly in France but also in Switzerland and Germany, for crimes including armed robbery. He had been flagged for extremism and was on a watch list.