Roadside bombs have killed 14 Afghan civilians and one member of the U.S.-led international military coalition in southern Afghanistan, Afghan and NATO authorities said Sunday. A minivan ran over one bomb Sunday in Arghistan district, along Afghanistan's border with Pakistan, said Ahmad Jawed Faisal, the spokesman for Kandahar province. Other civilians, who were riding on a tractor, arrived to help the dead and wounded, but the tractor struck a second bomb in the road, he added. Authorities were trying to determine how many people died in each blast. At least three other civilians were injured in the explosions, according to a report of the Associated Press. According to the United Nations, last year was the deadliest on record for civilians in the Afghan war, with 3,021 killed. Separately, a NATO service member was killed in another roadside bomb explosion Saturday in southern Afghanistan. So far this year, 224 NATO service members have been killed in Afghanistan.