This is what we know about the terrorists who carried out the deadly London Bridge attack:
Khuram Shazad Butt
A 27-year-old Pakistan-born British citizen who was known to police and MI5, and was the subject of a 2015 investigation.
He is alleged to have been an associate of jailed hate preacher Anjem Choudary and appeared in the 2016 Channel 4 Islamic extremist documentary The Jihadis Next Door.
The Jabir Bin Zayid Islamic Centre, where Butt occasionally worshipped, said he was once asked to leave "after interrupting a Friday sermon".
Mohammed Shafiq, chief executive of anti-extremism group the Ramadhan Foundation, said Butt called him a "Murtad" - traitor in Arabic - when he confronted Choudary about supporting terrorism days after the 2013 murder of Lee Rigby.
Residents at a block of flats in Barking, east London - where several arrests were made on Sunday - said Butt, known locally as "Abs" or "Abz", had lived in the area for around three years.
The father of two young children was a keen gym-goer and weightlifter, neighbours said.
Butt worked out at the Ummah Fitness Centre in Ilford, where a message on the door said: "While Mr Butt did occasionally train here at UFC gym we do not know him well nor did we see anything of concern, we will of course help the police in any way we can."
Transport for London (TfL) confirmed he worked for London Underground as a trainee customer services assistant for six months until he left in October 2016.
Housewife Erica Gasparri, 42, told The Times she had reported Butt to anti-terror police over fears he was attempting to radicalise schoolchildren, after challenging him in a park near a school.
A friend told the BBC Asian Network he reported Butt to the anti-terror hotline after he began expressing increasingly radical views and justifying terror attacks, but he was never arrested.
Another acquaintance recalled the "wonderful guy" playing football in the park with him and his children.
Police said he had appeared on the radar of security services but was in "the lower echelons of our investigative work".
Neighbour Ken Chigbo claimed the attacker, wearing the same Arsenal shirt, had come to ask him about hiring a van hours before the atrocity.
Rachid Redouane
Barking-based Redouane, 30, claimed to be Moroccan-Libyan, and also went by the name Rachid Elkhdar, claiming to be six years younger.
Security sources in Ireland confirmed the terrorist married a British woman in Dublin in 2012 and lived in Rathmines, Dublin.
It is not clear when he came to the Republic or how long he stayed but it is believed he used Irish jurisdiction to get a European Union permit which allowed him to be in the UK.
Redouane left Ireland after the wedding and may have travelled to Morocco before settling in the UK.
He returned to Ireland again in 2015, again for an unknown length of time, but Taoiseach Enda Kenny said he was not one of a small number of radicals under surveillance.
An Irish security source described the killer as having "extensive immigration history related to the UK".
The first clue to his background came when authorities found an Irish identity card on the body of one of the suspects.
Redouane, reportedly a former pastry chef, is said to have had a 17-month-old daughter with former wife Charisse O'Leary, a 38-year-old from Ireland.
Youssef Zaghba
A 22-year-old Italian national of Moroccan descent was living in east London and reportedly worked in a restaurant in the capital.
The Corriere della Sera newspaper said Fez-born Zaghba's Italian mother lived in the northern city of Bologna, having parted from his father and left their Moroccan home.
It reported that he was stopped by Italian police in March 2016 at Bologna's airport trying to get to Syria via Turkey, and that this was communicated by Italian intelligence to their UK counterparts.
But Scotland Yard said he was not a police or MI5 "subject of interest", despite Italian media reports to the contrary.
