The man who died when a homemade bomb exploded outside Liverpool Women’s Hospital has been named by police as Emad Al Swealmeen.
The 32-year-old was a passenger in a taxi when his device blew up shortly before 11:00 GMT on Remembrance Sunday.
The driver David Perry escaped before the car caught fire and has since been discharged from hospital.
Four men arrested in Liverpool under the Terrorism Act have been released from police custody without charge.
Meanwhile, the UK terror threat level has been raised to “severe”.
Officers believe Al Swealmeen lived at a house in Sutcliffe Street in the Kensington area of Liverpool, where counter-terrorism police officers carried out raids earlier.
Police said he had recently rented an address in Rutland Avenue, near Sefton Park in the city, which has also been searched by officers.
“Our focus is the Rutland Avenue address where we have continued to recover significant items,” said Det Ch Insp Andrew Meeks, from Counter Terrorism Police North West.
“Any information that the public may have about Al Swealmeen no matter how small may be of great assistance to us.”
In a later statement, police said they had made “significant progress” since Sunday and had 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”.
BBC News correspondent Ed Thomas said Al Swealmeen was a refugee from Syria who was befriended and supported by Malcolm and Elizabeth Hitchcott, who knew him as Enzo, when he arrived in the UK.
Mrs Hitchcott said she and her husband were “just so sad” and were “very shocked” by his death.
“We just loved him, he was a lovely guy,” she added.