London, UK: Police on Monday named two of the three men behind the London terror attack, saying one was known to security services but that there had been no intelligence about an attack.

Khuram Shazad Butt was 27 and a British citizen born in Pakistan, police said in a statement.

‘Khuram Shazad Butt was known to the police and MI5. However, there was no intelligence to suggest that this attack was being planned and the investigation had been prioritised accordingly,’ police said.

He appeared in a Channel 4 documentary entitled ‘The Jihadis Next Door’ about British extremists that was broadcast last year, British media reported.

Redouane was 30 and ‘claimed to be Moroccan and Libyan’. Police said he also used the name of Rachid Elkhdar and a different date of birth that gave his age as 25.

‘I would urge anyone with information about these men, their movements in the days and hours before the attack and the places they frequented to come forward,’ national counter-terrorism police chief Mark Rowley said in the statement.

‘At any one time MI5 and police are conducting around 500 active investigations, involving 3,000 subjects of interest.

‘Additionally, there are around 20,000 individuals who are former subjects of interest, whose risk remains subject to review by MI5 and its partners,’ he said.

Rowley said the security services had stopped 18 plots since 2013, including five since the Westminster attack two months ago.

Police said they now had 10 people in custody after releasing two of the 12 people arrested on Sunday.

The attack, claimed by the Islamic State group, saw three men wearing fake suicide vests use a white van to mow down people on London Bridge and then slash and stab revellers enjoying a Saturday night in the bustling Borough Market area.

Armed police reacted swiftly, killing the attackers within eight minutes with 50 shots.

Both men lived in Barking, an ethnically diverse part of east London where police carried out several raids on Sunday and Monday.

All 10 people still being held as part of the investigation were released without charge on Monday.

Police chief Cressida Dick said investigators had seized ‘a huge amount of forensic material’ from the attackers’ van.

‘A very high priority for us is to try to understand whether they were working with anybody else,’ she told BBC television.

She and Mayor Sadiq Khan visited London Bridge as commuters returned to work after some security cordons were removed, and hundreds of mourners turned out later for a vigil on nearby Tower Bridge.

‘To the sick and evil extremists who commit these hideous crimes, we will defeat you. You will not win,’ Khan said to applause.

The Amaq news agency, which is affiliated with the IS group, said the attacks were carried out by ‘a detachment of fighters from Islamic State’.

A Canadian and a Frenchman were among the dead and citizens of several nations were among the 48 injured, including Australia, Bulgaria, France, Greece and New Zealand.

Eighteen are still in critical condition, according to health authorities.