The Italian police officers who shot and killed a Berlin terrorist attacker on the run have been transferred from their original location near Milan.

As a precautionary measure, the officers will no longer be employed in Sesto San Giovanni, the news agency Ansa reported on Sunday, citing local police.

The Italian Interior Ministry made the decision after reports that a police chief had warned about the possibility of a retaliatory strike in reaction to the killing.

The 24-year-old attacker, Anis Amri, drove a lorry into a row of stalls on a Christmas market in central Berlin on December 19, killing 12 and injuring more than 50, many of them seriously.

He was shot dead by Italian police near Milan on December 23 after drawing a gun and wounding one of the officers during a routine check.

Investigators used film footage from video cameras at a railway stations to trace Amri's escape from Germany across the Netherlands, Belgium, France and then to Italy.

Shortly after shooting Amri, officials were criticized for mentioning the names of the police officers involved in the operation.

Among others, Italian Prime Minister Paolo Gentiloni und Interior Minister Marco Minniti publicly thanked the officers.