Human Rights Watch reports:
The US Joint Special Operations Command (JSOC), which is a semi-covert arm of the military, and the Central Intelligence Agency (CIA) are estimated by research groups to have carried out 81 targeted killing operations in Yemen: one in 2002 and the rest since 2009. The strikes by drones, warplanes or cruise missiles by various counts have killed at least 473 combatants and civilians. The United States has also carried out hundreds of targeted killing operations, primarily by drones, in Pakistan and a small number of such strikes in Somalia.
After many years of neither confirming nor denying such strikes, President Obama and other top US officials began publicly acknowledging the targeted killings program in 2010. However, citing national security concerns, the administration has provided only the barest information about individual strikes. For example, US authorities have not revealed the number of strikes, the number of civilians and alleged combatants killed or wounded, or, with a few exceptions, the target of the strikes. Moreover, the administration’s legal rationale for such killings, outlined in various speeches and “fact sheets” by the government in the past two years, has been inadequate.
Amnesty International finds:
According to NGO and Pakistan government sources the USA has launched some 330 to 374 drone strikes in Pakistan between 2004 and September 2013. Amnesty International is not in a position to endorse these figures, but according to these sources, between 400 and 900 civilians have been killed in these attacks and at least 600 people seriously injured.