Security video shows Liverpool taxi explosion that UK police say was terrorist incident

• Surveillance footage shows the moment a taxi exploded outside of an England hospital on Sunday.
• Authorities said Monday that the incident is being treated as terrorism.

Surveillance video captured the moment a taxi exploded outside of an England hospital, killing a man inside, as authorities said Monday that the incident is being treated as terrorism.

CCTV footage, published by The Guardian, captured the taxi blast that was caused by an improvised explosive outside Liverpool Women's Hospital on Sunday.

Authorities said the sole passenger in the taxi - who died in the blast -had brought the explosive device into the cab.

Shortly before 11 a.m. local time, the taxi driver picked up a man in the Rutland Avenue area of Liverpool who asked to be taken to the Liverpool Women's Hospital, which was about 10 minutes away, said Russ Jackson, the head of Counterterrorism Policing for northwestern England.

When the taxi approached the hospital, the blast went off, engulfing the cab in flames, the surveillance video shows.

The driver escaped from the cab and suffered non-life-threatening injuries. He was hospitalized for his wounds and released, cops said.

Police say they know the identity of the passenger, but "cannot confirm at this time."

Three men, ages 21, 26, and 29, were arrested in the city on Sunday under the Terrorism Act in connection to the incident, while another 20-year-old man was arrested on Monday, authorities said.

"It is not clear what the motivation for this incident is," Jackson said, adding that police believe the passenger in the taxi built the improvised explosive device.

Jackson continued, "The reason why he then took it to the Women's Hospital is unknown, as is the reason for its sudden explosion."

The police official noted that remembrance events were taking place nearby the hospital at the time of the explosion and explained, "We cannot at this time draw any connection with this, but it is a line of inquiry we are pursuing."

"Although, the motivation for this incident is yet to be understood, given all the circumstances, it has been declared a terrorist incident and Counter Terrorism Policing are continuing with the investigation," Jackson said.

Liverpool Mayor Joanne Anderson said the taxi driver locked the doors of his cab so that the passenger inside could not exit, but police did not confirm that story, the Associated Press reported.

"The taxi driver, in his heroic efforts, has managed to divert what could have been an absolutely awful disaster at the hospital," Anderson told the BBC.