London terror attack: Neighbours report hearing shots fired as 12 are arrested

People watch police activity in Barking, east London, following last night's terrorist incident at London Bridge. . Photo: Stefan Rousseau/PA Wire

Residents said armed officers swooped on flats in Barking, east London, where they believe one of the attackers may have lived.

At least four police vans were stationed behind a cordon outside the Elizabeth Fry flats in King's Road.

MORE: Theresa May says UK is in the grip of copycat terror attacksVeronica Oladapo, 45, who lives in a neighbouring block, left her building at around 7am to see police taking four men and a woman away.

People (right) lie on the ground after being detained by police at Elizabeth Fry flats in Barking, east London, which officer raided following the terror attack on London Bridge. . Photo: Furqan Nabi/PA Wire

She said: 'When I came out they were already taking some of the casualties away.

'There were three of them ... the ambulance came and took them away.

MORE: Reassurance given to residents and visitors to Norfolk'There were another two sitting down inside.'

A person (centre) is led away by police at an address in Barking, east London, following last night's terrorist incident at London Bridge.. Photo: Stefan Rousseau/PA Wire

One of the men had a hood pulled over his head while another one used a jacket to hide his face, she said.

Damien Pettit, who lives in the same block in east London, was shown a photograph of one of the attackers.

MORE: Witnesses describe seeing speeding vehicle veer into crowds in LondonHe told Sky News he could not be certain it was the same person, but that it looked like a man who lived in the block.

A person is led away in handcuffs at an address in Barking, east London, following last night's terrorist incident at London Bridge. Photo: Stefan Rousseau/PA Wire

Mr Pettit said: 'If it is, I am completely shocked. He has lived here for three years.'

Adding that the man he knew had children, he continued: 'I am kind of absorbing this at the moment because I can't understand how it could have been him.

MORE: Seven dead, at least 48 injured, three attackers killed'He has always tried to help in terms of what is going on in the area.'

More than five hours after the first arrests, a woman in a burka was led into a police van parked outside the flats.

It then drove away with sirens blazing, followed by three other vans.

MORE: Prime minister under pressure to suspend general election after London terror attackScotland Yard said 12 people had been detained in Barking 'in connection with last night's incidents' and that searches at a number of addresses in the area were continuing.

Furqan Nabi, a witness to the early morning arrests, said he saw four men lying face down on the floor.

One looked over 50, and another man looked at least 60 years old and had a beard, the 35-year-old neighbour said.

MORE: Leaders and politicians from Norfolk and around the world reactA third man was in his late 20s or early 30s, he said. He could not see the fourth man properly.

Around 20 emergency services vehicles were present, he added.

A scaffolding truck parked inside the police cordon by the block of flats just before 2.30pm.

MORE: Stabbings reported as police respond to 'terrorist incidents'Workers began bringing equipment round to the right hand side of the apartment block where the flat belonging to those arrested is thought to be.