All seven aboard the plane died. Among those killed was radio operator Sgt. Jeannette L. Winters, 25, of Gary, Indiana, the first woman to be killed in the U.S.-led war on terrorism, Operation Enduring Freedom. 

"Our hearts and prayers go out to the families of the soldiers. But I want to remind them that the cause that we are now engaged in is just and noble. The cause is freedom," President Bush said Wednesday evening. 

He said the plane was on a "multi-mission stop" and its final destination was the base at Shamsi. The plane had left from Jacobabad in central Pakistan. 

While the cause of the accident is under investigation, the Pentagon said there was no indication of enemy fire, but that has not been ruled out. An investigation is under way. 

Witnesses reported the plane appeared to be on fire on its final approach when it struck the mountainside. 

All the victims were from the Marine Corps Air Station Miramar, north of San Diego, California, said Major T.V. Johnson. Four of them were married, he said, and some had children. 

"I can tell you that they were proudly serving their country, I can tell you that they were there when their nation called, and they unfortunately gave their lives," Johnson said. "It's a tough time for their families. It's a tough time for the Marines who were part of the Marine family." 

Bruce Bertrand, father of one of the Marines, confirmed his son Bryan's death and said he was informed personally by two Marines on Wednesday afternoon. 

Scott Peters, Bryan's brother-in-law, said Bryan will be missed. "We just are all very proud of Bryan, he was a wonderful member of the family," he said. 

A total of 18 Americans have died since the beginning of Operation Enduring Freedom, including one CIA agent killed while interrogating Taliban fighters at a prison near Mazar-e Sharif. The other 17 were military personnel