Two men have been arrested in Londonderry by officers investigating a car crash that killed a policewoman.

The 27-year-old officer died when her patrol car was involved in a collision with a suspected stolen vehicle overnight.

She was on routine patrol when the fatal incident happened at around 3.40am. Two other officers in the police car sustained non-serious injuries.

Police had been hunting for two males who made off from the scene on the Limavady Road in the direction of the Ebrington area. The arrested men are aged 23 and 25. They are currently being questioned in police custody.

Northern Ireland's chief constable has vowed to bring to justice those responsible for the car crash.

Matt Baggott said he was greatly saddened by the death of his colleague.

"This is a personal tragedy for her family and also for the whole Police Service," he said.

"She was out on duty, working to keep people safe, when she died. My thoughts and prayers are with her family at this time. I and my colleagues will ensure that no stone remains unturned as we work to bring to justice those who perpetrated this crime".

Stormont Justice Minister David Ford said his thoughts were with the policewoman's relatives and the injured officers. He said: "I was shocked to hear of this tragic incident which resulted in the death of a police constable who was carrying out her duties serving the community in the middle of the night. My thoughts and prayers are with her family at this time.

The Northern Ireland Police Ombudsman's office has been informed. Police have appealed for witnesses to come forward.