Armed French police have launched an operation in Strasbourg's Neudorf neighbourhood as they pursue the hunt for a gunman who killed three people in an attack on a Christmas market.
Elite officers from the RAID police unit fanned out along one street on Thursday, some with their guns trained on the houses in front of them.
Other officers extended a security perimeter in the neighbourhood.
Interior Minister Christophe Castaner told the Senate that police were acting on a lead and "eliminating any doubts".
There was no immediate indication they had located the suspect shooter.
Hundreds of police have also been scouring eastern France for the fugitive gunman behind the deadly attack, as flowers and lit candles were left at the site in the eastern French city.
More than 700 officers are involved in the hunt for 29-year-old Cherif Chekatt, who has a long criminal record, had been flagged for extremism and was on a watchlist as a potential security threat.
Government spokesman Benjamin Griveaux told CNews television the focus was on catching the suspect as soon as possible, no matter whether he was dead or alive.
Chekatt allegedly shouted "God is great!" in Arabic and sprayed gunfire during Tuesday's rampage near Strasbourg's Christmas market.
The death toll was increased from two to three on Thursday.
The dead included a Thai tourist, 45-year-old Anupong Suebsamarn, according to the Thai Foreign Ministry.
Thirteen others were wounded, with five in serious condition, the prefecture of the Strasbourg region said.
Italian Interior Minister Matteo Salvini said one Italian was among the wounded who was in a critical condition.
The Europhonica radio consortium said Antonio Megalizzi, 28, was in Strasbourg to follow the session of the European parliament.
Prosecutors have opened a terror investigation into the attack.
Police have distributed a photo of Chekatt, who was wounded in an exchange of fire with security forces, with the warning: "Individual dangerous, above all do not intervene".
France has raised its three-stage threat index to the highest level and deployed 1800 additional soldiers across France to help patrol streets and secure crowded events.
Benjamin Griveaux called on "yellow vest" protesters not to take to the streets. Some members of the movement have planned a fifth round of demonstrations on Saturday across France to demand tax relief.
The usually busy streets of Strasbourg were eerily empty on Thursday morning, with a heavy police and military presence.
The Christmas market was closed at least through Thursday, authorities said.
Some lit candles and brought flowers to a makeshift memorial at the site of the attack.
"You can feel a very heavy atmosphere due (to) all these events," resident Lucille Romance said.
"People are in a state of shock and are avoiding getting out of their house."
French authorities said that the suspect, born in Strasbourg, had run-ins with police starting at age 10 and his first conviction was at 13.
Chekatt has been convicted 27 times, mostly in France but also in Switzerland and Germany, for crimes including armed robbery.
Australian Associated Press
