Heavy security measures are being implemented in central Italy ahead of the he 60th anniversary of the Treaty of Rome this weekend. The Italian government, as well as 40 European heads of state, are set to take part in events in the capital Rome on Saturday (25 March).

Security experts said the threat of possible terror attacks and infiltration by masked protesters known as "black blocks" was high.

"We don't have the possibility of lowering our guard," Foreign Minister Angelino Alfano was quoted by news agency Ansa as saying. He made he remarks following an extraordinary meeting of Italy's anti-terror unit (CASA), police and intelligence services on 23 March.

Interior minister Marco Minniti said: "Italy will further strengthen checks in areas with large influxes of people. All the police and intelligence officers will be engaged non-stop in the anti-terrorism front, in order to identify every source of possible risk."

The meeting occurred days after a terror attack in London left at least five people, including the attacker, dead.

Rome on lockdown

Security will be beefed up in crowded places and areas of Rome where demonstrations are set to take place over the weekend. Protesters have organised at least four marches and two sit-ins, according to the Local.it.

At least 5,000 security agents will be deployed across the capital.

Police helicopters and drones will be flying to carry out surveillance, but civilian drones have been banned in Rome during the weekend.

Large vehicles such as trucks and vans have also been banned from entering certain areas. Some zones will be cordoned off and completely inaccessible to all vehicles.

Museums including the Roman Forum and the Colosseum will be closed from Friday evening till Sunday morning.

Some security measures applied in Rome will also be implemented in Norcia, Umbria region, where officials are set to visit survivors of last year's earthquake.