The group has been trying to expand in Algeria, where al-Qaida's North African branch and other Islamic extremist groups have been based and have long fought Algerian authorities.
The IS-affiliated Amaq news agency said yesterday in a statement that IS fighters shot the officer and seized his weapon in the attack on Friday in Constantine, 400 kms east of the capital Algiers.
It later posted a picture of what it said was the officer's gun. Algerian authorities confirmed the police officer was killed by an unnamed "terrorist group," but didn't provide details or comment on the IS claim. The attackers are at large.