British police arrested Twelve men on Sunday after raiding the home of one of the men behind the London attack, Sky News reported.
A woman was also arrested but was released following the raid by armed officers at 7:00 am (0600 GMT) in Barking, east London, the broadcaster said.
London’s Metropolitan Police would not confirm the arrests or the raid, although an AFP reporter at the scene said there were several police vehicles outside a block of flats that had been cordoned off.
Three men rammed a vehicle through crowds of pedestrians on London Bridge on Saturday, before attacking revellers with knives, leaving seven people dead and 48 in hospital.
The assailants were shot dead at the scene, although police are still seeking to establish whether they had accomplices.
Metropolitan Police Commissioner Cressida Dick earlier told reporters: “We believe the threat that they posed was neutralised.
“Of course it’s a very complex and confused scene, and a confused series of events.
“So it’s important that we first of all make sure there is no one else outstanding. We don’t believe there is, but we must make absolutely certain of that.
“We have a very large investigation ongoing, and we will be seeking to establish whether anyone else was working with or assisting in any way or helping in the planning of this attack.”