- Liverpool hospital blast
Image caption, Al Swealmeen reportedly converted to Christianity after moving to the UK
Four men arrested under terrorism laws following a bomb explosion outside Liverpool Women's Hospital on Sunday have been released without charge.
It comes after police named Emad Al Swealmeen as the man who died when a homemade device blew up in the back of a taxi shortly before 11.00 GMT.
It is understood the 32-year-old was an asylum seeker from the Middle East and converted to Christianity in 2017.
Police say "important evidence" has been found at an address he rented.
In an update on Monday evening, Assistant Chief Constable Russ Jackson, head of Counter Terrorism Policing North West, said the property at Rutland Avenue near Sefton Park, in the south-east of the city, was "becoming central to the investigation".
This was the address where Al Swealmeen was picked up by the taxi before being driven to the maternity hospital.
ACC Jackson said: "We have made significant progress since Sunday morning and have a much greater understanding of the component parts of the device, how they were obtained and how the parts are likely to have been assembled."
But he said it could take weeks to establish how the incident was planned and prepared.
Four men were arrested in the Kensington area of Liverpool – three aged 21, 26 and 29, who were held on Sunday, and a 20-year-old man who was detained on Monday.
ACC Jackson said: "Following interviews with the arrested men, we are satisfied with the accounts they have provided and they have been released from police custody."
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Reports suggest Al Swealmeen formally converted from Islam to Christianity at a ceremony in Liverpool's Anglican Cathedral. The cathedral, which was the scene of the city's main Remembrance Day service on Sunday, is a short distance from Liverpool Women's Hospital.
After his conversion, Al Swealmeen briefly lived with a local couple, Elizabeth and Malcolm Hitchcott, at their home.
Mrs Hitchcott told the BBC she was "just so sad" and "very shocked", adding: "We just loved him, he was a lovely guy."
Another address in Sutcliffe Street in the city, where officers believe Al Swealmeen previously lived, is also part of the investigation.
The taxi driver David Perry escaped before his car caught fire and has since been discharged from hospital.
The UK terror threat level was raised from "substantial" to "severe" on Monday, meaning an attack is "highly likely", because the explosion in Liverpool was the second incident in a month, following the death of Conservative MP Sir David Amess.
Deputy Assistant Commissioner Matt Twist, one of Counter Terrorism Policing's senior national co-ordinators, said the change was a "precautionary measure and not based on any specific threat".
Investigators are being cautious about drawing conclusions about the motivation of Emad Al Swealmeen.
He is believed to have originally come from the Middle East and went into the asylum system. But in recent years he may have converted to Christianity and also suffered from mental health issues.
The decision to declare this a terrorist incident looks less to be based on a clear understanding of his ideology and more on his methodology, with the use of an improvised explosive device.
However, investigators will still be hoping to gain a better understanding of what exactly lay behind this incident.
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