At least 20 killed in Pakistan blast

KABUL, Afghanistan — At least 20 people were killed in an explosion in the Pakistani tribal areas Tuesday, while residents reported seeing an aerial drone firing at least two missiles immediately before the blast.

Pakistani military officials said the explosion happened at a terrorist-training camp when militants attempting to build bombs accidentally set them off. Maj. Gen. Waheed Arshad, a Pakistani military spokesman, denied the blast came from a missile strike. "It was not from outside," he said. He said more than 20 were killed.

Pakistani TV stations, citing intelligence sources, reported an attack had been launched from within Afghanistan, where tens of thousands of U.S. and NATO troops are operating.

The United States has previously carried out attacks against suspected terrorists in the tribal areas, even though the Pakistani government forbids foreign troops from conducting military operations on its soil.

Maj. John Thomas, a spokesman for NATO-led forces in Afghanistan, said late Tuesday he had no information on the blast. Army Lt. Col. David Accetta, a U.S. military spokesman in Bagram, Afghanistan, said: "We were not involved with any strike into Pakistan. ... U.S. forces did not fire into Pakistan with missiles or airstrikes or anything else."

The explosion took place just across the border from Afghanistan near the village of Mami Rogha, which is about 25 miles west of Miran Shah, the main town in North Waziristan.

Local residents said they had seen a drone hovering above the area immediately before the blast and at least two missiles fired from the drone had destroyed a religious school and several adjacent houses.

Associated Press material is included in this report.