At least 70,000 people in the Greek city of Thessaloniki are being evacuated so that a 500lb World War Two bomb can be defused, officials say.

It is thought to be one of the largest wartime bombs to be found in urban Greece in addition to being one of the largest mass evacuations.

The bomb was discovered during road works last week and is due to be disposed of on Sunday.

Officials say it is too degraded to tell if it is German or an Allied bomb.