Washington (CNN) -- The Federal Aviation Administration has restricted all planes traveling over Iraq from flying at or below 30,000 feet, a threshold similar to the altitude of a Malaysian airliner that was downed over Ukraine.
The FAA restriction issued late Thursday comes in response to fighting in Iraq between government forces and rebel militants from Islamic State in Iraq and Syria, or ISIS.
The new Notice-To-Airmen (NOTAM) from the FAA also prohibits flights into and out of Erbil and Sulaymaniyah.
Erbil, the capital of Iraq's semiautonomous region of Kurdistan, and Sulaymaniyah, a Kurdish controlled city, have been considered safe havens in the conflict, both housing thousands of refugees.
The US has said Malaysia Airlines flight 17 was shot out of the sky by a surface-to-air missile, likely manned by Russian-backed separatists in Ukraine. That disaster, on July 17, killed all 298 people on board, and raised fears about the safety of international flights over conflict zones.