A 14-year-old suicide bomber detonated explosives near the heavily barricaded NATO headquarters in Kabul on Saturday, killing six civilians including children, NATO and local officials said.
The bomber wore a vest packed with explosives and rode right up to the NATO gates on a bicycle, underscoring the insurgents' ability to strike deep inside the Afghan capital, ahead of the withdrawal of most foreign combat forces by the end of 2014.
Pieces of flesh and splattered blood lay on the street near the base, where the small bodies of children were lifted into ambulances. Scores of young children peddle trinkets and chewing gum around the foreign bases, hoping to earn a bit of cash.
The Taliban took responsibility for the attack, but denied they had deployed a teenage bomber, saying instead he was a 28-year-old who targeted the Kabul offices of the U.S. Central Intelligence Agency (CIA).
NATO's International Security Assistance Force (ISAF) condemned the use of children. "Forcing underage youth to do their dirty work again proves the insurgency's despicable tactics," said spokesman Brigadier General Gunter Katz.
Ministry of Interior spokesman Sediq Sediqqi said six civilians were killed in the attack, which took place just before noon, and five more wounded, including children.
Security was beefed up across the capital on Saturday as celebrations were underway to commemorate the 11th anniversary of the death of Ahmad Shah Massoud, the hero of the 1980s war against Soviet forces, and later a fierce opponent to the Taliban.
Massoud was killed on Sept. 9 by al Qaeda militants posing as reporters.
The Saturday bombing was the latest example of how militants are able to strike the most secure parts of the Afghan capital even after more than a decade of fighting Western forces with far superior firepower.
President Hamid Karzai blamed Afghan intelligence officials and NATO for failing to prevent the last major insugent attack in Kabul, when a group of insurgents stormed several buildings in the diplomatic quarter in April, resulting in an 18-hour stand-off between security forces and militants.
Sediqqi speculated on his Twitter feed that Saturday's attack may have been carried out by the Haqqanis, the most experienced insurgents in Afghanistan.
On Friday the United States said it is designating the Haqqani network -- blamed for a number of high-profile attacks on Western and Afghan targets in Kabul -- a terrorist organisation.
Senior Haqqani commanders told Reuters from an undisclosed location that the move showed the United States was not sincere about peace efforts in Afghanistan and warned of more attacks on American forces in Afghanistan.