A manhunt is under way after a policeman was mown down and killed by a stolen pick-up truck.
The officer was standing on a central reservation when the stolen Mitsubishi, being pursued by police following a burglary, mounted the kerb and hit him at speed before driving off.
The stricken officer was given emergency first aid by colleagues and rushed to hospital but was pronounced dead shortly afterwards, Merseyside Police said.
The stolen vehicle was found abandoned a short time later.
The force has launched a murder investigation following the incident in Wallasey, Merseyside, at around 2.08am today.
It said the neighbourhood patrol officer had been deployed following a burglary at an estate agent's premises in Woodchurch Road, Birkenhead, just after 1am.
During the burglary the raiders stole the red Mitsubishi pick-up, which was spotted by a police patrol at 1.28am.
It was being driven at speed and, when it was spotted by a police patrol car, a pursuit began.
The Mitsubishi was travelling along Wallasey Dock North Road in Wallasey when it mounted the central reservation where the two neighbourhood officers were standing after deploying a "stop stick" - a device used to stop stolen cars during pursuits.
The vehicle struck one of the officers and was then driven off. It was found abandoned soon afterwards in Corbyn Street, Wallasey.
Colleagues carried out CPR on the injured officer at the scene of the incident and he was then taken to Arrowe Park Hospital, where he was pronounced dead.
The officer's family have been informed and a family liaison officer is providing support.
Detectives are examining CCTV footage in a bid to identify the offenders.
Wallasey Road North, Corbyn Street and the premises in Woodchurch Road, Birkenhead, have been cordoned off while forensic examinations are carried out.