Eleven Afghan civilians were killed when an American warplane pursuing enemy attackers mistakenly bombed a house near Afghanistan's eastern border with Pakistan, the US military said yesterday.

　　The civilians were killed when the bomb landed on the home on the outskirts of Shkin, 220 kilometers south of the capital, the military said, calling the deaths a "tragic incident."

　　The killings occurred after unidentified assailants attacked a checkpoint manned by soldiers allied to American forces near the town, the military said from its headquarters at Bagram Air Base, north of the capital, Kabul.

　　There was no immediate reaction from Afghan authorities, but the incident was sure to produce outrage.

　　The last major civilian casualties caused by American-led forces in Afghanistan occurred on July 1, 2002, when 48 civilians were killed and 117 were wounded by a US Air Force AC-130 gunship that attacked several villages in Afghanistan's Uruzgan province.

　　Afghan officials and survivors said at the time that most of the dead were women and children celebrating a wedding at a compound in the Deh Rawod area. They said the only gunfire from the area came from celebrants shooting their riflessintosthe air. No anti-aircraft weapon was ever found.

　　Yesterday, two Harrier attack aircraft were called in and spotted two groups of five to 10 enemy fighters each. One of the planes dropped a 1,000-pound laser-guided bomb, but it missed its intended target, the military said.

　　"The bomb missed the intended target and landed on the house. The circumstances of the bombing are being investigated," it said in a statement.

　　The US military said four Afghan fighters were injured in the initial fighting and evacuated to a nearby US base. They were in stable condition.

　　No US soldiers were injured. It was not clear what happened to the enemy fighters.

　　Further details were not immediately available, but the military said an investigation was underway.

　　Over 10,000 coalition troops - 8,000 of them American - have been hunting down rebel fighters from the former Taliban regime, al-Qaida, and their allies, including former Prime Minister Gulbuddin Hekmatyar.

　　There have been several rocket attacks and ambushes in recent weeks near Shkin, a key border crossing point from Pakistan. US military officials believe rebel groups are launching incursionssintosAfghanistan from Pakistan.

　　Afghan authorities say Taliban remnants are reorganizing in an effort to destabilize the fledgling government of US-backed President Hamid Karzai.