(KUNA) -- A clash between Taliban fighters and coalition and Afghan forces and air strikes left at least 19 militants dead in southern Afghanistan, Afghan officials said on Thursday. Coalition officials confirmed the clashes and air strikes but did not give the exact number of casualties. Spokeswoman for the coalition Capt Julie Roberge told journalists there was a clash in the Nauzad district of the southern Helmand province. However, they did not have the casualty figure at the moment. But a provincial government spokesman said seven fighters, who attacked the district of Nauzad, were killed in exchange of fire while 12 others were killed in air strike. Mohyuddin, spokesman for the provincial governor in Helmand, said the insurgents, armed with heavy and light weapons, attacked the centre of the district last night. He said they were trying to occupy headquarters of the district.The coalition and Afghan forces retaliated and their attack was repulsed, said the spokesman. He added seven militants were killed in the clash while the rest fled the area. As they were retreating, the coalition war-planes targeted one of their vehicles resulting in the killing of 12 more fighters and the wounding of two others said the spokesman. He said the fighting continued for several hours. Security situation in the southern provinces is slipping from bad to worse at a time when the NATO forces are about to take command from the US-led coalition forces in the troubled parts of the country. Two days back, the US Defence Secretary, during a brief visit to Kabul, admitted the insurgency was on rise in the south but vowed they would not let Taliban succeed. The British had stationed 3,300 troops in Helmand province. In face of the rising insurgency, the British government recently announced sending 900 more troops along with helicopters to the troubled region.