Police are looking for two men that left the scene where a 27-year-old officer died in a road crash involving a suspected stolen vehicle.
The officer was travelling in a police car on routine patrol when the incident happened in Londonderry last night.
Two other officers in the patrol car sustained non-serious injuries.
Police have appealed for witnesses to come forward.
More top news
All this week while reporting, I have been taking photos. They offer powerful portraits of the lives affected by the desperate outbreak.
Some of the world's biggest football clubs will ask FIFA to move the 2022 World Cup to spring.
After saying she wanted "just a card" for her birthday Betty Musker is celebrating her 104th with over 6,000 cards from around the world.