SANAA : An apparent US drone strike and ensuing ground clashes in Yemen killed three suspected Al-Qaeda militants and two soldiers on Sunday, a security official and witnesses said.The strike targeted a house in Wadi Abida, in the eastern province of Marib, and killed two suspected militants, the official said, requesting anonymity.He said an arms cache in the house exploded but did not identify the suspects killed.Witnesses said the strike was carried out by an unmanned aircraft of the sort that Washington has increasingly deployed against Al-Qaeda targets in Yemen which shelters what it regards as the jihadist network's most dangerous branch.A tribal source said the strike was followed by ground clashes in which two Yemeni soldiers and a militant were killed.US drones strikes in Yemen nearly tripled in 2012 compared with 2011, from 18 to 53, according to the New America Foundation, a Washington-based think-tank.Al-Qaeda loyalists seized large swathes of the south and east in 2011, taking advantage of a decline in central government control during an 11-month uprising that forced veteran president Ali Abullah Saleh from power.Governments troops have since recaptured much of the territory with support from US drone strikes but the jihadists retain bases in the desert east.