The U.N. Human Rights Council agreed Friday, over the strong objections of the United States, to study whether American drone strikes comply with international law.

The resolution, which was drafted by Pakistan and co-sponsored by Yemen, both countries where the U.S. has undertaken multiple drone strikes, was adopted on a 27-6 vote, with 14 abstentions. The United States, Great Britain and France all voted no, but several NATO allies abstained.

Human rights advocacy groups, led by New York-based Human Rights Watch, mounted a strong campaign to garner support for the the motion.

In a letter circulated to the 47-members of the council on Thursday, the advocacy group argued that while currently only the U.S., Great Britain and Israel use armed drones in operations against alleged terrorists, it cautioned “that other states, and non-state actors, may acquire them in the future.”

Human Rights Watch also said it has “serious concerns that some if not many U.S. drone attacks may violate international law.”

A report published earlier this month, by Ben Emmerson, the U.N. independent expert on the promotion and protection for human rights and fundamental freedoms found that a U.S. drone strike in October 2006 at a religious seminary in Chenagai in the Bajaur tribal region of Pakistan killed up to 80 people instantly, 69 of whom were children.