Amnesty International and Human Rights Watch each issued reports on missile strikes carried out by unmanned drones. AI said it reviewed 45 drone strikes in Pakistan from January 2012 to August and found many of those killed in the attacks were not tied to terrorism.
"We cannot find any justification for these killings," Mustafa Qadri, a Pakistan expert for Amnesty International, said in a statement Tuesday.
The rights group said a U.S. "license to kill" may extend beyond the basic standards of international law. The organization said it wanted to see those responsible for alleged violations of international law held to account.
Human Rights Watch issued a similar report Tuesday on drone missile strikes in Yemen. A suspected CIA drone missile strike killed U.S.-born Anwar al-Awlaki, the ideological leader of Yemen's al-Qaida in the Arabian Peninsula, in 2011. Since then, a number of high-level al-Qaida figures have been killed or targeted in Yemen by U.S. drone missile strikes.
Human Rights Watch said civilians were killed in at least two drone strikes in Yemen. Letta Tayler, a terrorism analyst for the rights group, said some of the U.S. targets in Yemen were questionable.
"Yemenis told us that these strikes make them fear the U.S. as much as they fear AQAP," she said.