UK counter terrorism police have arrested three people following a blast outside a hospital in Liverpool.
One person was killed and another was wounded on Sunday when a vehicle exploded.
Police said they understood that the car involved was a taxi that pulled up at the hospital shortly before the explosion occurred.
The blast happened just as a Remembrance Day Service was commemorating war dead at the nearby Liverpool Cathedral.
Chief Constable Serena Kennedy gave an update on the investigation:
"Work is still ongoing 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, and out of caution, counter-terrorism police are leading the investigation supported by Merseyside police."
The three men have been arrested under the Terrorism Act.
Aged between 29 and 21, the men were detained in the Kensington area of the city.
Police said the explosion had not been declared a terrorist incident at this stage.