KABUL, Afghanistan — Two Pakistani border guards were killed by a U.S. bomb Sunday after a joint operation in a violent and unsettled corner along the Afghan border unexpectedly erupted in gunfire between the allies, authorities said Tuesday.
A U.S. military spokeswoman said that a U.S. F-16 fighter dropped the bomb after a Pakistani soldier opened fire on a U.S. patrol searching for Al Qaeda and Taliban remnants near the border town of Shkin, site of a Special Forces base and yards from the Pakistani border.
U.S. and Pakistani sources said the operation was being carried out with the full knowledge and cooperation of Pakistan. Nevertheless, when a U.S. soldier ordered a Pakistani guard to retreat to his side of the frontier, the guard opened fire, wounding one soldier and prompting the U.S. airstrike.
Details of the incident, still somewhat confused, didn't emerge until two days after the U.S. military -- without divulging the circumstances -- reported that the U.S. soldier received minor head injuries. It was unclear why the Pakistani border guard opened fire.
The border region is tense. Sgt. Steven Checo was killed in a firefight near Shkin on Dec. 21, the first U.S. combat death since May.
Pakistani authorities confirmed that two of their border guards were killed in the bombing. But the U.S. military and the Pakistani Interior Ministry said Tuesday that the incident had been smoothed over and that efforts were being made to ensure that no such clash happened again.
"We understand certain risks in these kinds of operations," an Interior Ministry spokesman said in Islamabad, the Pakistani capital. "Pakistan is not in a position to put the blame on anybody."
Still, the incident is believed to be the first in which Pakistani soldiers have died from U.S. firepower since America's war on terrorism began in October 2001. As many as six Pakistani soldiers were injured over the summer when a U.S. bomb mistakenly landed on a border station in North-West Frontier Province.
Pakistani authorities offered no explanation of how the Sunday incident came about, saying only that U.S. military operations close to the border are always executed with their knowledge and cooperation.
Ever since it drove the Taliban from power in November 2001, the U.S. military has found Afghanistan's southeast border area to be a source of trouble. It is thought to be a refuge for Taliban and Al Qaeda survivors who frequently harass U.S. bases and patrols with rockets, grenades and gunfire.
Although the American military has generally praised Pakistan for its anti-terrorism cooperation -- including its placing of 60,000 troops along the border and arresting 400 Al Qaeda and Taliban suspects -- top U.S. military brass, including Afghan theater chief Lt. Gen. Dan K. McNeill, have recently hinted that Pakistan should do more to beef up its border forces.
The wounded American, whose name had not been released, was "a member of a patrol assisting a Pakistan unit on a routine mission," the U.S. military said in a statement released at the Bagram military base near Kabul, the Afghan capital.
"A Pakistani border scout opened fire with a G3 rifle after the U.S. patrol asked him to return to the Pakistan side of the border," the statement said. The border guard and "several others retreated to a nearby structure. Close air support was requested, and one 500-pound bomb was dropped on the target area," the statement said.
Times special correspondent Talat Hussein in Islamabad contributed to this report.