The controversial U.S. drone strike program in the Middle East aims to pinpoint and kill terrorist leaders, but new documents indicate that a staggering number of these "targeted killings" affect far more people than just their targets.

According to a new report from The Intercept, nearly 90 percent of people killed in recent drone strikes in Afghanistan "were not the intended targets" of the attacks.

Documents detailing a special operations campaign in northeastern Afghanistan, Operation Haymaker, show that between January 2012 and February 2013, U.S. special operations airstrikes killed more than 200 people. Of those, only 35 were the intended targets. During one five-month period of the operation, according to the documents, nearly 90 percent of the people killed in airstrikes were not the intended targets. In Yemen and Somalia, where the U.S. has far more limited intelligence capabilities to confirm the people killed are the intended targets, the equivalent ratios may well be much worse.

The report, compiled from classified documents released by a source in the intelligence community, corroborates the many news accounts of civilian deaths caused by drone strikes. U.S. drone strikes have killed scores of civilians in Afghanistan, Pakistan, Yemen and Somalia since 2009.

In December 2013, a drone strike in Yemen killed 14 people returning from a wedding. Government officials mistook their vehicles for those of al Qaeda militants. Parents in Pakistan have reported taking their children out of school to protect them from possible strikes.

The U.S. government has implemented targeted killings since the Sept. 11 attacks as a counterterrorism measure and as retribution against al Qaeda and the Taliban. Under the Obama administration, many of these targeted killings have been carried out using unmanned drones. Despite the high number of civilian casualties and criticism that the program lacks transparency, President Barack Obama has repeatedly defended the strikes.

"The terrorists we are after target civilians, and the death toll from their acts of terrorism against Muslims dwarfs any estimate of civilian casualties from drone strikes," he said in 2013.

While government officials claim the drone strikes are accurate and rarely harm innocent civilians, strikes can kill or injure anyone in the area, even if they are only meant to kill a targeted individual.

“Anyone caught in the vicinity is guilty by association,” the source of the documents told The Intercept. When “a drone strike kills more than one person, there is no guarantee that those persons deserved their fate. … So it’s a phenomenal gamble.”

Read The Intercept's full series, "The Drone Papers," here.

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