KANDAHAR (Reuters) - A suicide bomber killed an Afghan interpreter working for US forces in an attack on a customs office in Afghanistans southern Kandahar province Monday, police said. The bomber appeared to target US troops meeting Afghan customs officials at the compound near the main city in Kandahar province, the heartland of the Taliban-led insurgency. The NATO-led International Security Assistance Force (ISAF) said one person was killed and five wounded, including two ISAF service members. Kandahar provincial police chief Mohammad Mujahid told Reuters that the interpreter was killed when a teenage suicide bomber blew himself up near a group of US soldiers and Afghan officials. In a separate incident in the south Monday, an ISAF service member was killed by a homemade bomb, ISAF said without giving any further details. A child has also been killed inadvertently in an airstrike during ISAF operations in southern Helmand province, the NATO-led force said. The child was found dead in a compound near the target of the strike. In eastern Khost province, insurgents wearing Afghan army uniforms ambushed and killed a provincial official in the Baak district, Khost police chief Abdul Hakim Esaaqzai said. Civilian casualties, often caused by airstrikes and night raids, have long been a source of friction between the Afghan government and its Western partners.