Militants with the Islamic State group on Wednesday shot down an Iraqi military attack helicopter, killing the two pilots on board in the second such incident in a week and raising concerns about the extremists’ ability to attack aircraft amid ongoing U.S.-led airstrikes.

According to two Iraqi officials, the militants used a shoulder-fired missile to take down the Bell 407 helicopter, which crashed just north of the refinery town of Beiji, located about 200 kilometers (130 miles) north of Baghdad.

The pilot and co-pilot were both killed in the attack, a military aviation official told The Associated Press. A Defense Ministry official confirmed the information. Both officials spoke on condition of anonymity in line with regulations. […]