The United States might have killed a dozen civilians in a wedding procession during a drone strike in Yemen last December, a human rights group claims.
Human Rights Watch on Thursday called on the U.S. government to investigate the strike, publish its findings and rectify any wrongdoing.
The United States already has investigated the strike twice, according to officials cited in The Associated Press, and concluded that only members of al Qaeda were killed.
According to a report from Human Rights Watch, the strike killed 12 men and wounded 15 other people, including the bride.
Officials in the U.S. and Yemen told the group the strike targeted members of al Qaeda in the Arabian Peninsula. Witnesses and relatives said they were all civilians, according to Human Rights Watch.
The strike, which was previously reported, took place Dec. 12 on an 11-vehicle procession in southern Yemen.
The Human Rights Watch report acknowledges members of al Qaeda may have been in the procession. However, it said that would not justify disproportionate killing by U.S. forces if civilians were present as well.
According to The Associated Press, the target of the strike was Shawqi Ali Ahmad al-Badani, an al Qaeda leader. He was wounded during the strike but escaped, according to officials cited by the AP.
He was accused of plotting an attack last year that spurred the United States to close 19 diplomatic posts in the region, according to the AP.
Human Rights Watch said the strike shows the Obama administration failed to meet the guidelines for lethal force President Obama outlined last year.
Obama’s guidelines require “near certainty” that no civilian casualties would result from lethal force.
Lethal force is only warranted when capture is out of the question and it is used to prevent an attack against the United States.
The White House did not directly address the strike. But in a statement to the AP, National Security Council spokeswoman Caitlin Hayden said the U.S. investigates any strike that might have killed civilians.
“When we believe that civilians may have been killed, we investigate thoroughly,” Hayden said. “In situations where we have concluded that civilians have been killed, the U.S. has made condolence payments where appropriate and possible.”