Twelve people have been arrested after the London terror attack which left seven people dead and 48 injured.

The arrests in Barking, east London, followed a raid by police at a flat owned by one of the three attackers.

A white van hit pedestrians on London Bridge at about 22:00 BST on Saturday, then three men got out and stabbed people in nearby Borough Market. They were shot dead by police minutes later.

Condemning the attack, Theresa May said it was “time to say enough is enough”.

Controlled explosions were also carried out at the flat in Barking on Sunday morning.

It is the third terror attack in the UK in three months, following the car and knife attack in Westminster in March, which left five people dead, and the Manchester bombing less than two weeks ago, in which 22 people were killed.

Most political parties have suspended national general election campaigning, but the prime minister said full campaigning would resume on Monday and the general election would go ahead as planned on Thursday.

Eyewitnesses to the attack described seeing a van travelling at high speed along London Bridge, hitting pedestrians, before crashing close to the Barrowboy and Banker pub.

Three men then got out wearing fake bomb vests and began attacking people in the nearby market – an area known for its bars and restaurants, which were busy on a warm summer evening.

Four police officers who tried to stop the attack were among those injured, two of them seriously.

One of them was an off-duty officer and amateur rugby player who tackled one of the terrorists, suffering stab wounds.

Another, a British Transport Police officer who joined the force less than two years ago, took on the attackers armed with only his baton.

Metropolitan Police Commissioner Cressida Dick praised their “extraordinary bravery”.

The three suspects were eventually shot dead within eight minutes of the first 999 call being received.