Three U.S. soldiers were injured in two separate incidents in eastern Afghanistan and B-52 bombers were called in to protect a U.S. base that came under rocket attack, a U.S. military spokesman said Thursday.

Two U.S. Special Forces soldiers were treated for facial lacerations Wednesday after an explosive detonated under their vehicle 30 miles northeast of Jalalabad. A second device exploded without hurting anyone and a third was discovered unexploded.

Another U.S. soldier was hit in the abdomen by a gunshot Wednesday at Kandahar Air Field. Col. Roger King, a spokesman for the U.S. military in Afghanistan, said there was no hostile fire and the shooting was under investigation.

The soldier, who was not identified, underwent surgery at the Kandahar base in the southeast part of the country and was in critical but stable condition. He was expected to be airlifted to Landstul Regional Medical Center in Germany.

Early Thursday, officials at the U.S. base at Asadabad reported rocket fire over their compound. Jets and B-52 bombers were scrambled to provide air support, but the military would not say if the B-52s dropped any bombs.

Eastern Afghanistan is considered one of the most dangerous regions in the country. Asadabad is about 100 miles northeast of the capital Kabul and Jalalabad is about 60 miles east of Kabul.