Police have identified two attackers, and have yet to release the name of the third man who carried out a brutal attack Saturday night in central London, killing seven.
Police had already named Butt and Redouane, a 30-year-old who claimed to be Moroccan and Libyan.
British police have named the three men who carried out the terror attack in London on Saturday and who were all shot dead by police.
The trio killed seven and injured 48 in their rampage around London Bridge and Borough Market on Saturday night.
Armed officers killed all three within eight minutes of receiving a 999 call.More news: £35.5m Salah deal inches closer
Authorities say the threat is unprecedented, with 500 active investigations involving 3,000 individuals and 20,000 former subjects of interest.
The 30-year-old was held on suspicion of the commission, preparation or instigation of terrorist acts.
The accused however are not connected to the 1 June attack in the United Kingdom capital that left eight people dead, the police said on Thursday.
The terrorist attack was claimed by IS but there is no evidence to suggest there was any overseas link to the planning and execution of the attack according to statements by London's Metropolitan Police.
An Italian police source has said that Zaghba, who lived in east London, had been placed on a watch list, which is shared with many countries including the UK.
Italian authorities said Zaghba was stopped at the Bologna airport in 2016 and questioned in Italy, but never charged with a crime.More news: United Kingdom police warn use of fake explosive belts is 'new tactic'
Zagbha was stopped in March 2016 while trying to board a direct flight to Istanbul.
London authorities announced on Wednesday that three more men had been detained in connection with last weekend's deadly terrorist attack in the city. He has said cuts in the number of police officers have had an impact on the ability to prevent attacks. Because there have been calls made by a lot of very responsible people on this, who are very anxious that she was at the Home Office for all this time, presided over these cuts in police numbers and now is saying that we have a problem.
British media has reported that Mr Thomas was caught up in the attack with his girlfriend Christine Delcros as they were crossing the famed bridge. "I'm sure the police will look into what they knew, what they could have done, what they did do and if anything could have been done differently".
Questions have been asked of police after it emerged Butt had starred in a Channel 4 documentary, The Jihadist Next Door. Transport for London confirmed he worked for London Underground in customer services before leaving last October.
The hospital said Ms Boden was "an outstanding nurse and a hugely valued member of the staff team in Theatres Recovery, described by her colleagues as "one in a million" who always went the extra mile for the patients in her care".More news: Kevin Durant Received Text from Former President Barack Obama After Finals Win
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