Police investigating Saturday night’s terror attack in London say they know the identity of the three attackers who killed seven people and injured 48.
The Metropolitan Police said their names would be released “as soon as operationally possible”.
A van hit pedestrians on London Bridge at 21:58 BST on Saturday before the men stabbed a number of people in Borough Market. They were shot dead by police.
The so-called Islamic State group has claimed responsibility for the attack.
Police said on Monday morning that officers were searching two addresses in east London – one in Newham and another in Barking.
Scotland Yard added that a number of people had been detained.
Twelve people have been arrested in Barking after raids at a flat which is believed to be the home of one of the attackers. A 55-year-old man has since been released without charge.
London Bridge rail and Tube stations both reopened for entry and exit early on Monday morning, after National Rail said the police cordons in the area of the attack had been lifted earlier than expected.
The bridge and surrounding roads have also reopened.
Meanwhile, the first victim of the attack has been named as Canadian national Chrissy Archibald.
It has also emerged that two people said they had warned the police about the behaviour of one of the attackers.
Since 2013 security services in the UK have foiled 18 plots. A large proportion of those have involved suspects who set out to commit acts of violence similar to the attack on Westminster Bridge and London Bridge.