MOGADISHU (Reuters) - A U.S. air strike aimed at Somali Islamist militants killed six civilians instead, a lawmaker and relative of one victim said on Wednesday, raising further questions about the extent of civilian casualties from U.S. military operations.

Reuters could not immediately verify their allegations. U.S. Africa Command said that the strike killed five militants.

Mahad Dhore, a lawmaker from Somalia’s South West state, gave Reuters the names and clans of the six civilians he said were killed.

“A drone killed six people in a mini bus yesterday, including a 13-year-old boy named Abdifatah Farhan Mohamud,” he said. “Six of them were civilians and they were buried near the area where they were bombed by the drone, because they could not be carried as they were burnt into pieces.”

U.S. Africa Command said in a statement that Tuesday’s strike near Janaale town had killed “five terrorists” and added “while we currently assess that this air strike injured no civilians, we are aware of social media reports alleging civilian casualties ... U.S. Africa Command said it will review any information it has about the incident.”

Africa Command said it investigates any reports of civilian deaths, but so far it has only verified two civilian deaths in 2018 despite carrying out scores of strikes. There have been 26 strikes this year so far. There were 63 strikes last year.

It’s unclear how strikes are investigated or the dead identified as al Shabaab militants. Somalia’s bloody civil war means large swathes of the country are off limits to government forces or their allies.

The air strikes are largely aimed at the al Qaeda-linked al Shabaab insurgency, which is fighting to oust the weak, internationally-backed government and rule using the insurgency’s own strict interpretation of Islamic law.

Mohamed Aden Bare, who told Reuters he was the brother of the minibus driver, said his brother was a civilian and the others aboard the bus were farmers and local residents.

“The drone hit the front part of the mini bus which mybrother was driving. We found no trace of him save a small piece of flesh that was found stuck on the destroyed seat,” he told Reuters.

Last month a U.S. air strike in a town held by Somali Islamist insurgents killed a telecommunications worker, the man’s employer said. Africa Command said he was a member of al Shabaab.

International rights group Amnesty International released a report a year ago alleging U.S. strikes were killing civilians.

The report said 14 civilian had been killed in just five air strikes between 2017 and 2018. Africa Command initially denied the allegation but later concluded that two civilians died in a 2018 strike.

Somalia has been at war since 1991, when warlords in the Horn of Africa nation overthrew a dictator and turned on each other.