The suspected Berlin attacker has been killed in a shootout with police in the Italian city of Milan.
Marco Minniti, Italy’s interior minister, said police were conducting a routine patrol at 3am local time (2am GMT) when they stopped a man resembling Anis Amri.
“At the moment he was stopped, the man without hesitating took a pistol out of his rucksack and shot the police after they asked him for identification documents,” he told a press conference.
“The patrol immediately responded to the shooting. A police officer was injured but fortunately he is recovering in hospital.
Photos showed blood in a road in the district of Sesto San Giovanni, where forensic investigators were collecting evidence.
A train ticket found in Amri’s rucksack showed he had travelled to Italy from Paris, the DPA news agency reported. The possibility he managed to cross two international borders and enter the French capital while under a European arrest warrant was likely to provoke fresh criticism of EU-wide security efforts.
The pistol Amri produced may be the same weapon he used to kill the driver of the lorry he used to conduct the massacre.
Amri is believed to have hijacked the vehicle from its Polish driver Lukasz Urban as he was parked up in Berlin on Monday afternoon.
The lorry’s GPS showed it moved backwards and forwards “as if someone was learning how to drive it” before it drove around six miles to the Christmas market, accelerating to plough into stalls packed with locals and tourists.
Amri fled after the lorry came to a stop, leaving Mr Urban dead in the cabin with knife and bullet wounds. The gun was not recovered, prompting warnings during he was “armed and dangerous” from German prosecutors.
They offered a €100,000 (£85,000) reward for information leading to Amri’s arrest but his eventual discovery on Friday appeared to be coincidental.
No suggestion the suspected Isis supporter was in Italy was made public, with reports of the shooting coming as Danish police hunted a man matching Amri’s description in Aalborg.
There was also speculation he may have been hiding out in Berlin after police footage caught him entering a mosque linked to Islamist extremists in the German capital hours after Monday’s attack.
German authorities had attempted to deport the 24-year-old in June after rejecting his asylum application but a bureaucratic dispute with Tunisia over missing documents proving Amri’s nationality meant he could not be ejected from the country.
Revelations that he had been put under surveillance for six months after being linked to a previous terror plot stoked anger against security services for letting him slip through the net.
Amri’s brothers believe he may have been radicalised while serving a prison sentence for arson in Sicily, while he was wanted for armed robbery in Tunisia and known to deal drugs in Berlin.