Two leading human rights organizations have released investigative reports into U.S. drone strikes in Yemen and Pakistan.

Amnesty International, which focused on drones trikes in Pakistan’s tribal areas, and Human Rights Watch, which looked at attacks in Yemen, found that some drone strikes were carried out unlawfully and that civilians have been killed. Both organizations also called on the U.S. government to be more transparent on the drone program, which has been marked by secrecy over the years.

The U.S. drone strikes target the Taliban, other Islamist militant groups and Al Qaeda in Pakistan, while the drone attacks in Yemen target Al Qaeda in the Arabian Peninsula. But civilians have been caught up in the attacks, sowing anger at the U.S. and leaving ordinary people caught between militant groups and the the U.S. military and CIA.

Amnesty International looked at 45 drone strikes in North Waziristan between January 2012 and August 2013. Field researchers did detailed investigations into 9 drone strikes in Pakistan. Amnesty found that an October 2012 drone attack killed a 68-year-old grandmother named Mamana Bibi while she was picking vegetables and was surrounded by her grandchildren. The group also looked at a July 2012 attack that killed 18 workers–including a 14-year-old boy–who were about to start eating.

While the U.S. had claimed that they were “terrorists,” Amnesty’s investigation found no evidence for that assertion. “We cannot find any justification for these killings. There are genuine threats to the USA and its allies in the region, and drone strikes may be lawful in some circumstances,” said Amnesty’s Mustafa Qadri in a statement. “It is hard to believe that a group of labourers, or an elderly woman surrounded by her grandchildren, were endangering anyone at all, let alone posing an imminent threat to the United States.”

Human Rights Watch investigated six attacks in Yemen–one from 2009 and the others from 2012-2013. The group found that “two of the attacks killed civilians indiscriminately in clear violation of the laws of war; the others may have targeted people who were not legitimate military objectives or caused disproportionate civilian deaths.” One of the strikes targeted a passenger van in central Yemen, killing 12 civilians. The reported target of the strike was nowhere to be found.

Both groups called on the Obama administration to lift the veil of secrecy around the drone strike program. In May 2013, President Obama pledged more transparency in a major speech on counter-terrorism policy. But Amnesty says that promise “has yet to become a reality, and the USA still refuses to divulge even basic factual and legal information.” Human Rights Watch likewise is calling for more transparency and investigations into the killings.

“The US should investigate attacks that kill civilians and hold those responsible for violations to account,” said Letta Tayler, the author of the Human Rights Watch report. “It’s long past time for the US to assess the legality of its targeted killings, as well as the broader impact of these strikes on civilians.

The reports come as there is renewed focus on drone strikes, despite there being a noticeable decrease in the pace of the attacks over the past few months. The United Nations released two reports in recent weeks that called for more transparency from the Obama administration. Next week, survivors of drone strikes are set to testify for the first time ever in front of Congress. And on October 30, filmmaker Robert Greenwald will release his new feature-length documentary titled, "Unmanned: America's Drone Wars." Greenwald's film, based on his on-the-ground reporting in Pakistan, takes an in-depth look at the consequences of America's drone war.