Viterbo gets ready for "Bomba Day" after discovery of massive bomb buried for 80 years.

Around 36,000 people will be evacuated from their homes in the central Italian town of Viterbo on Tuesday while army experts defuse a massive unexploded bomb left over from world war two.

The long-lost bomb is one of the biggest ever found in Italy and was unearthed during construction works in the town, located about 100 km north of Rome.

The device weighs 2,000 kg - of which 1,300 kg is explosives - and reportedly belongs to the category of aircraft bombs dropped by the Bristol Blenheim Mk IV bomber, in 1944.

The discovery of the bomb on Via Alcide De Gasperi last month has prompted a major security and evacuation operation ahead of what the locals are calling "Bomba Day".

Everyone within 1,400 metres of the bomb must evacuate the area by 09.00 on Tuesday, with all activities in the "red zone" to be suspended, leading to the closure of all shops, schools and healthcare facilities.

Parking restrictions will be in place and the area will be completey cordoned off, with police using drones to ensure that everyone has vacated the zona rossa.

Authorities have set up several reception centres for the 36,000 evacuated residents (and their pets), laying on free shuttle buses for those who need transport.