The U.S. government often brags about the pinpoint accuracy of drone attacks, but more evidence is surfacing which contradicts that claim.
According to Amnesty International, a small group of miners and woodcutters were eating dinner under a tent when they were hit by a drone attack on July 6, 2012 in North Waziristan, Pakistan.
When family members and friends came to help the injured, another drone strike killed many of those first responders for a total of 18 victims, including a 14-year-old boy.
This is one example of what is known a "double tap" attack that is being used more often by the U.S.
"They appear to be targeting those who have come in to help those who are injured," Amnesty International's Mustafa Qadr told the BBC. "And that's particularly shocking."
"Let's assume the U.S. made a mistake in the first strike," said Qadr. "But in the second round it should have been clear that they were killing civilians. A child was killed. It's up to the US to tell us why they were targeted. In the absence of that, it's an unlawful killing."
Qadr has documented U.S. drone attacks in a new report for Amnesty International in conjunction with an investigation by Human Rights Watch.
In May, President Obama said that U.S. drone strikes in Pakistan, Yemen and other countries are "effective" and "legal.'
"Before any strike is taken, there must be near certainty that no civilians will be killed or injured, the highest standard we can set," added Obama.
However, according to Human Rights Watch and Amnesty International, the U.S. officials responsible for the drone attacks that have killed civilians may have committed war crimes.
The Guardian reports that the U.S. has repeatedly claimed very few civilians have been killed by its drone bombing campaign, which is conducted "consistent with all applicable domestic and international law."
However, Pakistan's prime minister Nawaz Sharif plans to tell President Obama to end the attacks in his country this week in Washington D.C.
In its report, Amnesty International agrees that some U.S. drone attacks in Pakistan may not violate international law, but states "it is impossible to reach any firm assessment without a full disclosure of the facts surrounding individual attacks and their legal basis. The USA appears to be exploiting the lawless and remote nature of the region to evade accountability for its violations."
"To accept such a policy would be to endorse state practices that fundamentally undermine crucial human rights protections that have been painstakingly developed over more than a century of international law-making."