Local officials in Afghanistan's southern Helmand province say a roadside bomb has killed 11 civilians.
A provincial government spokesman in the traditional Taliban stronghold said all the victims were traveling together in a vehicle on a road frequently used by international forces.
The spokesman blamed the attack on Taliban insurgents.
The blast in Nawzad district came as Afghan and international troops in Helmand continued scaling back combat operations in the town of Marjah. A two-week-old offensive has been clearing the town of insurgents and paving the way for an Afghan administration to take control.
Despite the gains, Pentagon officials warned Saturday that the situation in Marjah remains dangerous and roadside bombs are still the biggest threat.
U.S. officials have said that after controlling Marjah, international forces plan more comprehensive operations in the southern Afghan city of Kandahar.
Meanwhile, the Afghan government has begun taking over the U.S.-run detention facility at Bagram Air Base.
A Justice ministry spokesman told reporters in Kabul Saturday that the handover process will take up to a year as the U.S. military trains about 300 Afghan soldiers as prison wardens.
Human rights groups have charged that prisoner abuse has taken place at Bagram, including beatings and lengthy detentions without charge.