British police say they have carried out fresh raids and detained an undisclosed number of people in the investigation into an attack in the heart of London that left seven people dead.
"A number of people have been detained," police said in a statement after two early morning raids in east London on June 5.
London police chief Cressida Dick told BBC television that police had seized "a huge amount of forensic material" after going through the van the assailants used to plow into people on London Bridge "very, very carefully."
Dozens were injured, 21 of them critically, in the June 3 rampage at a popular nightlife hub around London Bridge by three men wearing fake suicide vests. The suspects were shot to death by police.
The extremist group Islamic State (IS) has claimed responsibility for the attack.
The police chief has said the attackers have been identified, but the names have not been released.
Dick told British media she would not release further details in what she described as a fast-moving investigation, nor would she say whether authorities were familiar with the men ahead of the attack.
Police said on June 4 they were holding 11 people, all arrested in raids on two addresses in Barking in east London.
British Prime Minister Theresa May said a series of attacks in Britain were inspired by what she called a "single, evil ideology of Islamist extremism" that represented a perversion of Islam and of the truth.
Speaking on June 4, May warned that Britain faced a new threat from copycat attacks.