The man who rammed a 7-ton truck into a crowded Christmas market in the heart of Berlin, killing 12 people and injuring 48, has been identified by German media as a 23-year-old refugee of Pakistani origin who arrived in the country via the ‘Balkan route’.

The suspect has been named as Naved B., a 23-year-old Pakistani who was registered as an asylum seeker in February this year, Spiegel reported, citing police and security sources. The report also said the Pakistani man could have used a fake ID and an alias.

DPA news agency said Naved B. came to Germany via the so-called ‘Balkan route’, a popular passageway for refugees spanning between the Aegean Sea and Central Europe. The suspect was reportedly known to police for minor offenses.

The suspect has also had a German temporary residence permit since June 2016, Die Welt reported, citing police.

Die Welt daily reported that the original driver of the truck, a Polish man, had been shot dead prior to the attack. Regional police officials said he was a victim, not a perpetrator.

A Polish haulier, who also was a cousin of the victim and owner of the truck, said he lost contact with the driver on Monday at 4pm local time, according to the newspaper. It is still unclear how the Pakistani suspect managed to get into the truck.

Ariel Zurawski, the haulier who owned the truck, told Polish television he noticed that the vehicle was maneuvering in a strange way before the attack. “Someone was making forward and backward movements as if he was learning how to drive,” said Zurawski. He added that “someone was in the cabin” by the time he lost contact with the original driver.

Earlier, 200 officers of the elite SEK counterterrorism unit stormed a large refugee center located at Berlin’s defunct Tempelhof airport. Four men are understood to have been questioned, but were not arrested, Die Welt reported.

German Chancellor Angela Merkel said in a televised address that the truck attack is likely to be an act of terrorism committed by a man “who came to Germany to seek asylum.”

She said the country does not want to be paralyzed by terror, and promised that the government will take all necessary measures to ensure public safety. She is expected to visit the crime scene on Tuesday afternoon.

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