Updated

Italian police say they have arrested five people connected to Anis Amri, the Tunisian who carried out the 2016 Berlin Christmas market truck attack and was later killed in a shootout with police in Italy.

In a tweet Thursday, police said one of the five was believed to have procured the fake Italian identity papers that allowed Amri, a failed asylum-seeker, to move around Europe.

Amri killed 12 people when he hijacked a truck and drove it into a crowded Berlin Christmas market on Dec. 19, 2016. The attack was later claimed by the Islamic State group. Using fake documents, he fled to Italy and died in a shootout with police near Milan four days later.

The arrests were the latest in a marked uptick in recent police operations targeting suspected extremists.