U.S.-led coalition and Afghan troops clashed with suspected Taliban militants in the volatile south and called in an airstrike that left four militants dead, the coalition said Tuesday. Militants attacked coalition and Afghan troops Monday in the Sangin district of Helmand province, The Associated Press quoted the coalition as saying in a statement. The troops called in an airstrike on a compound used by militants, it said. «As Taliban fighters began to flee, coalition aircraft engaged and killed four Taliban fighters who were attempting to escape,» the coalition said. In neighboring Kandahar, Taliban militants clashed with border police on Tuesday, leaving two militants dead and one officer wounded, said border security police Gen. Abdul Raziq. Suspected Taliban militants, meanwhile, ambushed an Afghan army convoy with rocket propelled grenades in southern Zabul province, killing two soldiers and wounding up to 14, officials said. The troops were attacked Monday as they were traveling on the main Kabul-Kandahar highway in Zabul, said Mohammad Omar, an official with the Afghan National Army. Fourteen wounded soldiers were brought to a NATO base in the province for treatment. Suspected militants fled the area after the ambush, Omar said. Afghan army regional commander Gen. Rehmatullah Raufi said Tuesday that two soldiers were killed and four wounded in the incident. The officials' differing figures could not immediately be reconciled. Also in the south on Monday, suspected Taliban attacked a police vehicle north of Kandahar city, leaving one policeman dead, said provincial police chief Esmatullah Alizai. The latest violence came days after NATO and Afghan troops retook Sangin district from militants as part of NATO's largest-ever offensive in Afghanistan, Operation Achilles, launched last month to flush out Taliban militants from the northern tip of opium-producing Helmand province. Afghan army commander Raufi said that several clashes with the Taliban over the past two weeks in Sangin have left 20 Taliban dead, including a regional commander. That number did not include the four killed in Tuesday's airstrike. He said there have been no casualties in the Afghan army.