The Northern Territory Police Force are investigating after a death in Nightcliff this afternoon. 

Around 5:15pm, it is alleged that an unknown male was stealing items from a supermarket on Progress Drive, Nightcliff.

A 71-year-old owner of the store allegedly confronted the male and asked him to return the items before the male allegedly stabbed him with an edged weapon and fled the scene on a bicycle.

Patrons inside the shop provided initial first aid and immediately contacted police.

Emergency Services responded immediately and attended the scene where CPR was commenced, and the 71-year-old man was pronounced deceased.

At this stage, police believe they have identified the offender, and efforts are currently underway to locate him.

Detectives are urging anyone who has information to make contact on 131 444 or make an anonymous report to Crime Stoppers on 1800 333 000, and quote reference P25111518.