Counter-terrorism police are investigating the explosion at Liverpool Women's Hospital.

One person died and a man is being treated for non life-threatening injuries after a car explosion at the Liverpool Women's Hospital.
One person died and a man is being treated for non life-threatening injuries after a car explosion at the Liverpool Women's Hospital. (AP)

British police have announced the arrests of three men after a car exploded in front of Liverpool Women's Hospital, killing one person and injuring another.

The three men, aged 29, 26 and 21, were arrested in Liverpool's Kensington district under the anti-terrorism laws, Greater Manchester Police said in a tweet.

The police said a male passenger in the car was declared dead at the scene, while the driver, who was also a man, was injured and remains in hospital in a stable condition.

British Interior Minister Priti Patel said in a tweet she is being kept regularly updated on the incident.

Police report that the car involved was a taxi that pulled up at the hospital shortly before the explosion occurred.

Chief Constable Serena Kennedy said police were called to reports of a car explosion just before 1100GMT on Sunday.

"Work is still ongoing to establish what has happened," she told media.

"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 police said the explosion had not been declared a terrorist incident at this stage.

Source: TRTWorld and agencies