Kabul: A large explosion rattled the headquarters of NATO's International Security Assistance Force (ISAF) in the heavily guarded diplomatic quarter of the Afghan capital, Kabul, on Saturday, the force said.
Privately owned Tolo TV said four children had been wounded in the incident, but that could not be independently verified.
"We are on lockdown while we try get more details on the explosion," an ISAF spokeswoman said, referring to when all personnel are not allowed to leave the base.
Celebrations were going on in Kabul to commemorate the 11th anniversary of the death of Ahmad Shah Massoud, the hero of the 1980s war against Soviet occupiers, and later of opposition to the Taliban.
Massoud was killed on September 9 by al Qaeda militants posing as reporters.