KABUL, Afghanistan — A suicide car bomber targeting NATO-sponsored aid workers killed at least three people and wounded 31 on Thursday in southern Afghanistan, an official said. The bomber detonated the explosives-laden vehicle outside the gates of an aid office Thursday morning in Lashkar Gah, capital of Helmand province, said Daud Ahmadi, a spokesman for the provincial governor. At least 31 people were wounded in the blast and the building was nearly destroyed, Ahmadi said. He said the bomber appeared to be targeting vehicles of a NATO-sponsored Provincial Reconstruction Team that were passing by the building at the time. Foreigners were inside the vehicles, Ahmadi said, but he could not confirm if they were among the casualties. Helmand has been one of the most volatile areas in the Taliban insurgency’s pushback against a U.S.-led initiative to bring southern Afghanistan under greater control of the central Afghan government. Elsewhere, a rocket fired by Taliban insurgents killed a woman and her child in eastern Afghanistan. Insurgents fired the mortar round during a battle Wednesday with Afghan army soldiers trying to clear militants from a stronghold in Kapisa province’s Alasay district, said the provincial governor’s chief of staff, Abdul Sabor Wafa. President Hamid Karzai and NATO’s commander for Afghanistan, Gen. John Allen, condemned the insurgents on Thursday for the civilian deaths.