The death toll from an attack at an air base in south Jordan has increased to three U.S. troops, after two who were critically injured later died, a U.S. military official confirmed.

The service members were in vehicles approaching the gate of a Jordanian training facility when they came under small arms fire, the official said. Jordanian news agency Petra identified the base as the Prince Faisal Air Base. The incident occurred just after noon local time.