An explosion that destroyed five fuel tankers outside the main U.S. base in southern Afghanistan (search) was an accident, not the result of a Taliban (search) attack, the U.S. military said Monday, citing the results of an investigation.
At least three drivers were injured in the blast early Sunday, and Afghan officials were quick to blame Taliban rebels.
But U.S. military spokeswoman Lt. Cindy Moore said the blast, which sent plumes of black smoke billowing over Kandahar, was caused by "faulty fuel tanks."
She said military investigators determined that the blast originated inside one of the trucks, not outside.
"More than likely it was some type of problem with the tank," she said.
Maj. Michael Hicks, an explosive ordnance control team commander, said transporting fuel is "a risky business."
"No evidence of any kind has been found that indicates the incident was the result of an attack or an improvised explosive device," he said in a statement. "There are no components or items that we would associate with such things."
The explosion took place just after 3 a.m. Sunday, while Pakistani and Afghan drivers were waiting to deliver fuel to the U.S. base at Kandahar airport. Tight security measures mean long waits for drivers delivering fuel to U.S. bases in Afghanistan.
Meanwhile, the military said Monday that one of its CH-47 (search) helicopters operating in the south made a "precautionary landing" near Kandahar after developing a mechanical problem. Moore said nobody was injured in the incident, which occurred early Sunday, and the helicopter was repaired on site.
A rapid reaction force was sent out to bring the soldiers on board safely back to base. Moore had no details on how many soldiers were on the helicopter when it was forced to land.
Separately, suspected Taliban rebels ambushed a patrol of Afghan soldiers in southwestern Oruzgan province, sparking a one-hour firefight, Gov. Jan Mohammed Khan told The Associated Press.
Two Taliban were killed in the fighting Sunday, and Afghan soldiers arrested a regional Taliban commander named Mullah Allah Noor (search). The other militants escaped into the mountains.