Speaking at the scene of the explosion, Serena Kennedy, the Merseyside Chief Constable, said: “Work is still going on to establish what has happened, and could take some time before we are in a position to confirm anything.

“We are keeping an open mind as to what caused the explosion but given how it has happened, out of caution, counter-terrorism police are leading the investigation, supported by Merseyside Police.”

The force added that “this has not been declared a terrorist incident at this stage although out of caution, CT detectives are leading as we try to understand the circumstances behind the explosion”.

Patients diverted to other hospitals

Liverpool Women’s Hospital said visiting access had been restricted “until further notice” and patients had been diverted to other hospitals “where possible”.

The statement said: “We have restricted visiting access to the hospital with immediate effect and until further notice. Where possible we have diverted patients to other hospitals until further notice. We are currently allowing ambulances to access the hospital in emergencies.

“We are reviewing our patient activity for the next 24-48 hours and patients should wait to be contacted for updates about any planned appointments or other attendance at the hospital.

“Our staff are being permitted to leave and enter the hospital under the supervision of Merseyside Police.

“We would like to say thank you for the co-operation and support of our patients, visitors and staff who have been impacted by this incident, in particular those members of staff who were at the scene at the time of the incident.”

Phil Garrigan, chief fire officer of Merseyside Fire and Rescue Service, said the car fire had been “fully developed” when two appliances arrived shortly after 11am.

He told reporters at the scene: “The operational crews extinguished the fire rapidly but as has been reiterated by the police chief constable, there was one fatality.

“Another individual had left the vehicle prior to the fire developing to the extent that it did. Our thoughts are with them and the families of those involved.”

Joanne Anderson, the mayor of Liverpool, said: “The incident at the Liverpool Women’s Hospital is unsettling and upsetting and my thoughts are with those affected. I’d like to thank the emergency services for their swift response and for bringing calm to the situation.”