In a statement on Sunday, Counter Terrorism Police North West said three men, aged between 21 and 29, were detained in the Kensington area of the northwest England.
They said they were continuing to ascertain the cause of the blast and working with Merseyside Police as the investigation continued “at pace”. The security service, MI5, was also reportedly assisting.
Armed police officers have carried out raids on properties on Rutland Avenue near Sefton Park, and Boaler Street in Kensington, cordoning off the area, in an operation reportedly linked to the explosion.
The incident took place just before 11:00 GMT on Sunday when a taxi carrying one passenger pulled up, Merseyside Police said. The passenger, who is yet to be identified, was declared dead at the scene.
The driver of the vehicle sustained injuries and is in hospital in a stable condition, the police said.
It added that the explosion had not been declared a terrorist attack, but counter-terrorism police were leading the investigation into the incident.
Prime Minister Boris Johnson and Home Secretary Priti Patel termed it an “awful incident”.
“I want to thank the emergency services for their quick response and professionalism, and the police for their ongoing work on the investigation,” he said on Twitter.
My thoughts are with all those affected by the awful incident in Liverpool today.
I want to thank the emergency services for their quick response and professionalism, and the police for their ongoing work on the investigation.— Boris Johnson (@BorisJohnson) November 14, 2021
Patel also tweeted that she was “being kept regularly updated on the awful incident”.
“Our police and emergency services are working hard to establish what happened and it is right they are given the time and space to do so,” she wrote.
I am being kept regularly updated on the awful incident at Liverpool Women’s Hospital.
Our police and emergency services are working hard to establish what happened and it is right they are given the time and space to do so.
Please follow @MerseyPolice for updates.— Priti Patel (@pritipatel) November 14, 2021
The Liverpool Women’s Hospital has reportedly restricted visiting access until further notice and said that it diverted patients to other hospitals “where possible.”