Hundreds of families have finally been allowed to return home after they were evacuated for nearly 24 hours as Army experts struggled to defuse an unexploded Second World War bomb.

A large swathe of Bethnal Green in east London was evacuated yesterday following the discovery of the 500lb (226kg) weapon, believed to have been dropped during the Blitz, in the basement of a house.

After bomb disposal experts succeeded in making the device safe, an Army commander said that the bomb could have caused 'mass destruction' and warned that it was even more dangerous than when it was originally dropped.

Hundreds of people spent the night in a local school after 2,000 homes were evacuated, and drivers have been warned to avoid the area due to the 200m exclusion zone which was placed around the weapon.

Removed: Soldiers pictured taking away a Second World War bomb from the London house where it was found

Danger: Bomb disposal experts examine an unexploded weapon found in a Bethnal Green basement

Work: Soldier from the Royal Logistics Corps are at the scene of the unexploded Second World War bomb

John Biggs, the mayor of Tower Hamlets, said today: 'I am pleased to announce that residents can return home as the unexploded bomb has been safely removed and defused.

'Many thanks to the emergency services who worked tirelessly with us to make the area safe as soon as possible.'

The Army commander in charge of the operation added: 'I can confirm that the device is a German WW2 air delivered bomb weighing 250kg which if detonated could cause mass destruction.

'The bomb has been in the ground for more than 70 years but unlike a fine wine does not improve with age. It is potentially more dangerous today than the day it was made.'

It took nearly a whole day to defuse the weapon because of the 'severely restricted access' to the cellar where the bomb had lain ever since it was dropped during a Luftwaffe raid.

Army experts diffused the bomb chemically but had to wait for the 'soak process' to take place before they could remove it from the site.

Police stationed in Temple Street in Bethnal Green, east London, after a 500lb bomb was found by contractors

A specialist bomb disposal unit is currently on the scene while residents and businesses have been evacuated to a nearby school outside of a 200m 'hazard zone'

Tower Hamlets council earlier said: 'Last night hundreds of residents stayed the night at Bethnal Green Academy, where they were put up on camper beds and fed.

'We’d like to thank everybody for their patience and understanding around this, and we’ll continue to update residents as and when we get more information.'

Dozens of local residents were evicted from their homes between 11pm and midnight last night after a reassessment of the threat led officials to widen the exclusion zone.

Student Farzana Begum was evacuated after midnight along with her parents and five siblings, and told she might have to stay away from her home indefinitely.

'The whole area was being evacuated in the afternoon and I went to ask a police officer if we would have to go and he laughed it off,' the 20-year-old said. 'Then at 12.30am they knocked on the door and said we did have to leave.

'We asked them how long we had and they just said "as soon as possible" so they made it seem like there was an imminent threat. I grabbed everything because I wasn't sure how long we'd have to be away.'

Residents will reportedly be unable to return to their homes for 24 hours. Witnesses said they had been told the bomb is a metre long and was found buried underground as builders were working in the basement

Raquel Batona, 29, added as she left Bethnal Green Academy today: 'Just after midnight, a policewoman knocked on our door and said that we were being evacuated and that's when I grabbed some stuff and came to the school.

'They have looked after us really well. There has been plenty of food and water and the people have been really polite and kind.

'It's been a long night and we are so tired so I'm really looking forward to getting back to my house now.'

A spokesman for the London Fire Brigade said: 'Our urban search and rescue crews provided equipment and assistance to Army bomb disposal crews who worked carefully to remove the bomb from the basement.

'A great deal of work was being carried out by firefighters, army, police and local authorities to safely remove and defuse this bomb. We'd to thank local residents for their patience.'

The area, just a mile from the City of London financial hub, is one of the most densely populated neighbourhoods in the capital, with families and young professionals living alongside dozens of small shops and offices.

A 200m 'hazard zone' has been set up around Temple Street in Bethnal Green, where the bomb was found

Emergency: It is understood the building was being renovated when the alarm was raised yesterday

Police were called to Temple Street in Bethnal Green at about 12.45pm amid reports a 500lb bomb was found by contractors

The bomb was found by contractors at a building site in Temple Street yesterday afternoon.

The Army unit had been working since 6pm to assess the bomb, while residents and businesses were taken outside of the 'hazard zone'.

Witnesses at the scene said they had been told the bomb is a metre long and was found buried underground as builders were working in the basement of a home.

Members of the Colchester-based 621 Explosive Ordnance Device squadron, which also detonated historic bombs found in Bermondsey and Wembley this year, took charge of the operation.

Residents and businesses took to Twitter yesterday to describe how police imposed their cordon.

Will Sweet wrote: 'Evacuated from work in #bethnalgreen. Someone dug up a WW2 bomb next door.'

One resident, who lives near the site, told the Evening Standard that she was escorted 'several blocks' by officers after they 'bashed on the door'.

It is understood the property is being renovated to create ten flats and that the device was found during a 'precautionary bomb survey'.

Another resident, Rachel Walker, told her Twitter followers it was going to be a 'minimum 24 hour evacuation'.

The incident comes just months after thousands of people were forced to flee their homes in Southwark after a 5ft Second World War bomb was discovered under a former pensioners' centre.

Residents were evacuated after the 1,000lb German ordnance was discovered by builders under the old site of the Southwark Irish Pensioners in March.