Concrete barriers have been installed at famous landmarks across Italy following the terror attack in Barcelona last Thursday.

Major tourist sites in Milan, Rome, Bologna and Turin are all stepping up security in pedestrianised areas. Although Italy has not suffered any attacks on its territory there have been repeated warnings by Isis that the country is on its hit list.

In Milan, concrete barriers appeared over the weekend in the streets leading up to the city’s main piazza which houses its famous cathedral. Streets leading up to the adjacent Galleria Vittorio Emanuele – the spectacular 19th-century shopping arcade – also had the structures installed.

Bologna and Turin put protective barriers in place to separate vehicles and pedestrians this weekend. In Bologna, security has been tightened around the Basilica of San Petronio.

The church has been the target of several jihadi plots because it houses a 15th-century fresco by the artist Giovanni da Modena which depicts the prophet Mohammed being tortured by devils.

Busy central streets in Palermo, Sicily’s capital, are also due to get new protective barricades and the city council of Florence said it was looking into installing similar structures. In Genoa and Naples, police patrols were stepped up.

On Sunday, Italian media reported that concrete blocks will protect the entrance to Via del Corso, Rome’s main shopping street and Via dei Fori Imperiali, the avenue that runs through central Rome from the Piazza Venezia to the Colosseum.

Concrete blocks are already in place on the Via della Conciliazione, the main road leading to St Peter’s square.

In response to the Barcelona attack, Italian interior minister Marco Minniti said last week: “I am amazed that a van could have driven undisturbed down La Ramblas in Barcelona.

“It is strange there were not extra security measures in a site so crowded with tourists and residents.”