Drone Strikes Killing More Civilians Than the U.S. AcknowledgesS

Two new reports from human rights groups show that U.S. drone strikes in Pakistan and Yemen have killed more civilians than American authorities have admitted and may, in some cases, have violated international law.

Amnesty International investigated nine U.S. drone attacks in Pakistan between May 2012 and July 2013. According to the group, more than 30 civilians were killed in just four of the strikes.

One such strike killed 10 civilians, including a 14-year-old, who were, at the time they were bombed, eating dinner inside a tent. Several minutes later, as rescuers arrived to treat the wounded, another missile attack struck the site, killing eight more civilians.

“The drones are like the angels of death,” Nazeer Gul, a shopkeeper in the village Miram Shah in Pakistan, where at least 19 civilians have been killed since January 2012, told the New York Times. “Only they know when and where they will strike.”

The Human Rights Watch, which conducted a separate investigation in Yemen, found that at least 57 civilians were killed in six attacks between 2009 and 2013, including 41 in a 2009 strike that was based on bad information from the Yemeni government.

And a 2012 airstrike in Yemen destroyed a mini-bus, killing a pregnant woman, three children, and eight others. That attack was also blamed on faulty intelligence from the Yemeni government, which compensated the victim's families.

The studies come just four days after a U.N. human rights investigator released a report on drone strikes in Pakistan. According to the the investigator, Ben Emmerson, about 2,200 people have been killed by drone strikes in Pakistan over the past decade, including at least 400 civilians and 200 “probable non-combatants.”

In May, President Obama announced changes to the drone program, saying it will be only be used when there's “near-certainty that no civilians will be killed or injured,” and promised to be more transparent about the operations, which are carried out by a secret CIA program in Pakistan and by the CIA and Joint Special Operations Command in Yemen.

While the number of strikes has dropped in recent months, the U.S. still refuses to release information about many of the attacks, according to the reports.

“We think these people were civilians, and the onus is on the U.S. government to prove otherwise,” Naureen Shah of Amnesty International, who helped write that group’s report, told the Los Angeles Times. “The U.S. government has this information and is withholding it.”