A suicide bomber killed eight American civilians in an attack at a military base in south-eastern Afghanistan yesterday.
The explosion happened inside Forward Operating Base Chapman in Khost province, near the Afghan border with Pakistan, US officials said. The base is a centre for civilians working on reconstruction projects, a key part of President Barack Obama's strategy to stabilise Afghanistan. The blast also injured an unspecified number people, none of whom were thought to have been US or Nato troops.
Asked whether the suicide blast occurred inside the base, one official said: "That's my understanding." Another senior official confirmed that the attack involved an explosive vest.
Many civilians working outside Kabul have retreated into army bases as the security situation in the country as a whole has deteriorated. Foreign aid agencies warned earlier this year that the shift into the military bases, and the use of military personnel to carry out development projects, risked a dangerous blurring of the boundaries between troops and civilians.
The number of civilians killed this year in Afghanistan has reached record levels, and yesterday's strike represents one of the largest losses of foreign civilian life since Western forces invaded the country in 2001. Suicide attackers targeted United Nations employees at a guesthouse in Kabul in October, killing five and wounding several others.
After that incident, UN Secretary-General Ban Ki-moon said Afghanistan and Pakistan were the most dangerous places for UN civilian staff.
Washington is sending 30,000 extra troops to Afghanistan in an attempt to stem the violence, with Nato members contributing thousands more. The Obama administration has also pledged a "civilian surge" in Afghanistan, sending hundreds of US experts to work on development projects that aim to undermine support for the Taliban and other insurgent groups.
Khost is one of the areas of Afghanistan where the Taliban insurgency is strongest, and most foreigners there are troops or working under military protection. In September a suicide bomber rammed a car into a military convoy of foreign forces in the area, killing one American. Afghan civilian casualties have also been increasing, raising tensions between the Afghan government and Western forces.
The attack came on the day that an Afghan presidential delegation investigating the deaths of 10 people in eastern Afghanistan concluded that civilians – including children – were killed in an attack involving foreign troops, disputing Nato reports that the dead were insurgents.
Asadullah Wafa, a senior adviser to President Hamid Karzai, told the Associated Press that eight children between the ages of 12 and 14 were among the dead discovered in a house in the Narang district of Kunar province. A Nato official has said initial reports from troops involved in the fighting on Sunday indicated that those killed were all young male insurgents.
Several hundred Afghans protested against the deaths yesterday in Kabul and the eastern city of Jalalabad, where they burnt an effigy of President Obama and a US flag, chanting "death to Obama and Karzai". In Kabul, protesters chanted: "Unity, unity, death to the enemy of Islam!" and a protester with a bullhorn called on Mr Obama to "take your soldiers out of Afghanistan".
Mr Wafa said he was convinced that all those killed in the Kunar incident were civilians. "I have talked to the principal of the school in the village and he gave us details about the killed children," he said. "The schoolchildren cannot be al-Qa'ida. I confirm they are innocent people killed by mistake. I talked to President Karzai about the findings."
The bodies had already been buried by the time Mr Wafa's team arrived, but Colonel Wayne Shanks, a spokesman for Nato's International Security Assistance Force in Afghanistan, said yesterday that America was investigating the allegations together with the Afghan authorities.