A suicide car bomber attacked a NATO armoured vehicle in the southern Afghan city of Lashkar Gah on Thursday, killing at least three civilians and wounding 31 others, an official said.
The bomber struck near the education department in what is the provincial capital of Helmand, a focus of attacks by Taliban insurgents.
"A suicide attacker detonated his Toyota sedan vehicle loaded with explosives on an armoured vehicle," Daoud Ahmadi, the spokesman for the Helmand governor, told AFP.
A child was among the dead and several women and children were wounded, he said, adding that the death toll could increase.
The commander of the Afghan forces coordination center in the province, Mohammad Ismail Hotak, said 30 Afghan civilians have been taken to hospital in Lashkar Gah.
He said 15 private vehicles were totally destroyed in the blast while several others caught fire.
Afghan security forces surrounded the area, and body parts of the dead could be seen at the nearby education department compound, a witness said.
British and Danish troops with NATO's 130,000 strong International Security Assistance force operate in Helmand.
Just over a week ago on January 18, two attacks in the province killed 17 people and wounded more than 20 others.
A suicide bomber on a motorcycle killed 10 civilians and two policemen in the first attack at a bazaar, while an intelligence official was among the dead in a second blast caused by a mine, which was claimed by the Taliban.
A day later a suicide bomber killed at least seven people and wounded eight in an attack at Kandahar international airport in neighbouring Kandahar province.
In that attack also, ISAF armoured vehicles were the target but there were no NATO casualties.
The latest deaths come as both sides have made moves towards peace talks, with the Taliban, toppled in late 2001 in a US-led invasion, announcing plans to open a political office in Qatar.
But the Islamic hardliners said this did not mean they had surrendered in the war against coalition forces, only that they would use their political wing alongside their military to achieve their aims.
The United Nations said the number of civilians killed in violence in Afghanistan rose by 15 percent in the first six months of last year to 1,462, with insurgents blamed for 80 percent of the killings.