At least four people were killed and two others were injured in a U.S. drone strike launched early Saturday morning at North Waziristan Agency (NWA).According to the media reports, the incident occurred near Miranshah early morning when US drone fired two missiles at a house.As a result, four persons were killed while two others were injured. The house was completely destroyed in the strike. This is the third U.S. drone strike in North Waziristan within the last four days and it is also the 15th of its kind in Pakistan since the beginning of this year. To date, at least 112 people have reportedly been killed in such strikes in 2012.