Four held as cops hunt associates
Counter-terrorism detectives are attempting to trace any associates of Khalid Masood as they mount a huge investigation to establish what triggered the terrorist's murderous rampage in Westminster.
Eleven people have been arrested as part of the inquiry, but Scotland Yard said only four remain in custody - two men aged 27 and 58 who were arrested in Birmingham on Thursday and a 32-year-old woman and a 35-year-old man who were arrested in Manchester on Friday. All are being held on suspicion of preparation of terrorist acts.
Six of those arrested have now been released from police custody and face no further action - two women aged 21 and 26 and four men aged 23, 26, 27 and 28 who were all arrested at addresses in Birmingham.
A 39-year-old woman arrested in east London has been released on bail.
Masood, a middle-aged Muslim convert who killed four people before he was shot dead by police, was born Adrian Elms and also called himself Adrian Russell Ajao.
Asked about where the 52-year-old had been radicalised, Scotland Yard's head of counter-terrorism Mark Rowley said: "Our investigation focuses on understanding his motivation, preparation and associates.
"While there is no evidence of further threats, you will understand our determination to find out if he either acted totally alone, inspired by terrorist propaganda, or if others have encouraged, supported or directed him."
Asked whether Masood had travelled overseas, he said: "We are looking at his history."
Detectives have seized 2,700 items from the searches, including "massive amounts" of computer data, while around 3,500 witnesses have been spoken to.
It is believed Masood stayed at the Preston Park Hotel in Brighton the night before he murdered four people.