The Berlin Attack suspect, Anis Amri, was shot dead in a Milan suburb on Friday.
Security for the long Christmas weekend was heightened throughout Italy and at the Vatican on Saturday following the killing by police of the man believed to be responsible for the Berlin market truck attack.
As investigators sought to determine if Anis Amri had accomplices in Italy, and associates of the 24-year-old were arrested in his home country of Tunisia, national security officials were taking no chances.
Rome authorities banned vans or trucks from entering the city centre and anti-terror police wearing masks and wielding machine guns set up roadblocks on routes leading to famous tourist sites or areas where crowds traditionally gather.
At the Vatican, where Pope Francis was due to celebrate Christmas Eve Mass in St Peter's basilica on Saturday evening, police cars and military jeeps stood about every 100 metres along streets leading to the Vatican.
Security was also stepped up in central Milan and other Italian cities, particularly near major churches where faithful were attending Christmas services.
After reconstructing Amri's movements since he drove a truck through a festive market in Berlin on Monday, killing 12 people, police are investigating whether he was seeking shelter from comrades in Italy or was enroute to another country.
The town where Amri was killed, Sesto San Giovanni, is home to a sizeable Muslim community and is a departure point for buses to southern Italy, eastern Europe and the Balkans.
Amri had travelled undetected to Italy from Germany via France, taking advantage of Europe's open-border Schengen pact. He was shot dead in the town on the outskirts of Milan early on Friday after he pulled a gun on police during a routine check.
In a video released on Friday after his death, he is seen pledging his allegiance to militant group ISIS leader Abu Bakr al-Baghdadi.
© Thomson Reuters 2016
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