3 US Service Members Killed in Gunfire at Jordanian Military Base

— -- Three U.S. service members died from gunfire today after their car approached the gate to King Faisal military base in Jordan, according to the Pentagon.

One U.S. service member was killed at the scene. Two others, who had been medevaced to King Hussein Hospital in Amman with critical injuries, died at the hospital, a U.S. military official told ABC News.

"We are saddened to report that three U.S. service members were killed today in a shooting incident at a Jordanian military base," Pentagon press secretary Peter Cook said in a statement. "The three service members were in Jordan on a training mission, and the initial report is that they came under fire as they were entering the facility in vehicles."

Jordan's state-run Petra news agency, which originally reported that two U.S. trainers had died, said the car failed to comply with orders to stop at an entrance and gunfire erupted.

In a statement on Facebook, the Jordanian military said a Jordanian Air Force officer was also injured in the gunfire outside the base in the southern city of Al-Jafr.

An investigation by the Jordanian military is underway to determine the cause of the incident.

"We are working closely with the government of Jordan to determine exactly what happened," the Pentagon statement said. "Our thoughts and prayers are with the loved ones of these service members. We will provide more information as appropriate."

ABC News' Ben Gittleson contributed to this report.