A 27 year-old female PSNI officer has died following a road traffic collision in Derry involving a police vehicle and another vehicle, believed to be stolen.
The incident occurred in the early hours of Saturday.
The police vehicle in which the female officer was travelling was on routine patrol. Two other officers in the car sustained non serious injuries.
Two males made off from the scene in the direction of Ebrington.
The Limavady road remains closed at its junction with Glendermott Road and Clooney Terrace. The road is expected to remain closed for some time.
Police are appealing for witnesses to contact them. Anyone with any information is asked to contact Strand Road Police Station on 0845 600 8000. Or if someone would prefer to provide information without giving their details, they can contact the independent charity Crimestoppers and speak to them anonymously on 0800 555 111.
As standard procedure, the Police Ombudsman has been informed.