A US drone strike targeting a compound killed five persons in North Waziristan near the Afghan border on Wednesday, security officials said. "Several US drones flew into the area before dawn and fired four missiles on a compound, killing five suspected militants," a security official told AFP after the strike in Hurmuz area, east of Miranshah, the capital of North Waziristan tribal region. Another security official in the northwestern city of Peshawar confirmed the attack and casualties. The identities of those killed in the strike was not immediately clear. The attacks by unmanned US aircraft remain contentious -- they are deeply unpopular in Pakistan, which says they violate its sovereignty and fan anti-US sentiment, but American officials are said to believe they are too important to give up. Wednesday's strike is the 32nd of its kind (counted on daily basis) in 2012. So far this year at least 227 people have been killed in such strikes. Casualty figures are difficult to obtain, but a report commissioned by legal lobby group Reprieve estimated last month that 474 to 881 civilians were among 2,562 to 3,325 people killed by drones in Pakistan between June 2004 and September 2012.