A gunman killed at least three people and wounded 12 others near a Christmas market in the French border city of Strasbourg on Tuesday evening before being cornered by police.
About 600 security agents are hunting for the gunman, Strasbourg-born Cherif Chekatt, 29, who fled the scene.The mother, father and two brothers of the Strasbourg shooting suspect are being held in custody for questioning, said sources close to the investigation.
The Strasbourg prefecture said the gunman shot dead three people, revising down a previous death toll of three.
Police officials said Chekatt was wounded in a gunfight with soldiers after the Tuesday night attack but escaped, and a top official said he might have escaped to neighboring Germany.
"The hunt is continuing," Deputy Interior Minister Laurent Nunez said on France Inter radio. Asked whether the suspect might have left France, he said: "That cannot be ruled out."
With the gunman on the run, France raised its security threat to the highest alert level, strengthening controls on its border with Germany as elite commandos backed by helicopters hunted for the suspect.
French and German agents checked vehicles and trams crossing the Europa Bridge on the Rhine river, along which the Franco-German frontier runs, police said, backing up traffic in both directions. Hundreds of French troops and police were taking part in the manhunt.
It was unclear if the market — a popular gathering place and the nucleus of an al-Qaida-linked plot in 2000 — was the intended target. The assailant got inside a security zone around the venue and opened fire from there, Mayor Roland Ries said on BFM television.
A terrorism investigation was opened, but the motive of the attack is unclear. Nunez said eight of the injured are in serious condition, and the city mayor said some had head wounds.
The motive was not immediately clear but, with France still on high alert after a wave of attacks commissioned or inspired by Islamic State militants since early 2015, the counter-terrorism prosecutor opened an investigation.
French military spokesman Col. Patrik Steiger said the shooter didn't seem to be aiming at soldiers patrolling in and around the market, but appeared to target civilians instead.
Some three hours after the attack, elite police cornered the suspect and shots were fired, a source close to the operation said. French media reported the assailant was holed up in a store on the Rue Epinal.
Interior Minister Christophe Castaner said the gunman was known to security services, and the local prefecture said he was on an intelligence services watchlist. Chekatt had been imprisoned in Germany in 2016 and 2017 on theft charges, and was deported to France in 2017, a spokeswoman for Germany's BKA criminal police said.
People in the city's Neudorf area and Etoile park were told to stay where they were as officers hunted the shooter on the ground and from the air.
The European Parliament, which is sitting in Strasbourg this week, was put into lockdown.
The Christmas market was being held amid tight security this year, with unauthorized vehicles excluded from surrounding streets during opening hours and checkpoints set up on bridges and access points to search pedestrians' bags.
The Paris prosecutor said the motive for the attack was not known. No group immediately claimed responsibility but the U.S.-based site Intelligence Group, which monitors jihadist websites, said Islamic State supporters celebrated the attack.
Police had searched the suspect's home early on Tuesday, before the attack during a homicide investigation, Nunez said. Five people have been questioned as part of that investigation.
President Emmanuel Macron was was being updated as events unfurled, an Elysee Palace official said. Castaner was on his way to Strasbourg, which lies on the border with Germany.
The gunman entered the market over a bridge at about 8 P.M. before opening fire, the prefecture said, adding that the suspect was a known security risk and on a watch list.
A spokesman for the European Parliament said the building had been shut down and staff ordered to stay inside.
"My thoughts are with the victims of the Strasbourg shooting, which I condemn with the utmost firmness," tweeted Jean-Claude Juncker, head of the European Commission, the EU executive. "Strasbourg is an excellent symbol of peace and European Democracy. Values that we will always defend."
The attack took place at a testing time for President Emmanuel Macron, who is struggling to quell a month-long public revolt over high living costs that has spurred the worst public unrest in central Paris since the 1968 student riots.
The revelation that Chekatt was on a security watchlist will raise questions over possible intelligence failures, but some 26,000 individuals suspected of posing a security risk to France are on the "Fiche S" watchlist. Of these, about 10,000 are believed to have been radicalised, sometimes in fundamentalist Salafist Muslim mosques, online or abroad.
European security agencies have feared for some time that Islamist militants who left Europe to fight for Islamic State in Syria and Iraq would return after the jihadist group's defeat, with the skills and motivation to carry out attacks at home.
Secular France has been grappling with how to respond to both homegrown jihadists and foreign militants following attacks in Paris, Nice, Marseille and beyond since 2015.
In 2016, a truck ploughed into a Bastille Day crowd in Nice, killing more than 80 people, while in November 2015, coordinated Islamist militant attacks on the Bataclan concert hall and other sites in Paris claimed about 130 lives. There have also been attacks in Paris on a policeman on the Champs-Elysees avenue, the satirical weekly Charlie Hebdo and a kosher store.
Almost exactly two years ago, a Tunisian Islamist rammed a hijacked truck into a Christmas market in central Berlin, killing 11 people as well as the driver.