Islamic State group militants shot down an Iraqi military helicopter, officials said Saturday, killing the two pilots onboard and raising fresh concerns about the extremists’ ability to attack aircraft amid ongoing U.S.-led coalition airstrikes.

The attack happened late Friday in the Shiite holy city of Samarra, about 95 kilometers (60 miles) north of Baghdad. A senior Defense Ministry official told The Associated Press the Sunni militants used a shoulder-fired rocket launcher to shoot down the EC635 helicopter on the outskirts of the city.

An army official corroborated the information. Both spoke on condition of anonymity as they weren’t authorized to speak to journalists. […]