MOGADISHU (Reuters) - A raid involving U.S. troops in Somalia has caused a rift between the precarious U.S.-backed government and a powerful clan that says innocent farmers were massacred, months after President Donald Trump approved stepped-up operations there.

Family members mourn Mohamed Mohamud who was killed in an attack by Somali forces supported by U.S. troops in Bariire village in Mogadishu Somalia, August 29, 2017. REUTERS/Feisal Omar

The U.S. Africa command, Africom, has acknowledged that U.S. forces participated in a ground operation in support of Somali troops in the village of Bariire last week, and says it is investigating reports of civilian deaths.

It did not reply to further questions from Reuters about the incident, the second mission in Somalia this year in which it has acknowledged the participation of U.S. ground troops. A Navy Seal was killed in a raid in May.

Last week’s raid took place in an area that had been occupied by al Shabaab Islamist militants but was recaptured by government forces earlier in August.

Residents from the Habar Gidir clan, a powerful group spread across southcentral Somalia, said some villagers had weapons, but only to protect themselves from a rival clan. They said the villagers had nothing to do with militants, who had been driven away before the government forces and U.S. troops launched their raid on Friday.

“It was after morning prayers when I heard gunshots. I jumped over a wall made of iron sheets and the boy went out through the small gate,” said Muktar Moalim Abdi, 47, whose 13-year-old nephew was killed in the raid, about 50 km (30 miles) from the capital.

“They told me the boy was shot as he tried to take cover under the banana trees,” said Abdi, one of 10 relatives of the victims that spoke to Reuters along with three witnesses of the raid itself. Their statements give the most detailed public account yet of last week’s raid.

The relatives and witnesses were not able to say conclusively whether U.S. forces present during the raid had opened fire, or whether all the shooting was carried out by the Somalis that the Americans were accompanying.

The Somali government’s initial account described those killed as Islamist fighters, although within hours it issued another statement acknowledging that civilians had reportedly been killed.

A government commission set up to investigate is due to report on Thursday. Somali officials have meanwhile declined to comment further.

Somalia has been in a state of civil war since 1991. It now has an internationally-backed government, supported by African peacekeepers, battling al Shabaab, an al Qaeda-affiliated militia which has attacked civilians in neighboring states.

It is one of half a dozen countries, including Afghanistan, Yemen, Iraq, Syria and Libya, where Washington acknowledges conducting military operations against militants.

In March, Trump gave the U.S. military in Somalia greater authority to carry out strikes and raids, including without waiting for militants to attack U.S. allies. Ramped up operations followed, with Africom reporting eight U.S. airstrikes from May to August this year, compared to 13 for the whole of 2016.

In the case of last week’s raid, a veteran Western expert on the security situation in Somalia said it seemed likely that the U.S. troops had “been drawn into local clan dynamics” by whoever supplied their intelligence.

“The real question is, what was the source of the intelligence and why did they believe it?”

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U.S. officials acknowledge that developing the intelligence needed to pursue al Shabaab takes longer than in, say, Iraq or Syria, where the U.S. military devotes vastly more resources. Somalia’s complex tribal dynamics are also a complicating factor.

Two U.S. officials, speaking on condition of anonymity, described Somalia as an “economy of force” effort for the U.S. military, meaning fewer resources were available there than on other battlefields.

GUNFIRE IN THE MORNING

Mohamed Hassan Amin said he and his pregnant wife survived because they ran outside and hid in a banana grove when the deadly gunfire began. They initially thought it was an attack by the rival clan and were relieved to see armored vehicles, which they thought meant the African peacekeeping force and government troops had come to keep them safe.

“My friend said, it looks like AMISOM and Somali forces came to rescue us,” Amin told Reuters by phone. Then, the Somali troops spotted them and surrounded them at gunpoint, he said. About a dozen white soldiers were present.

“The white men told us to lie down. A translator helping one asked ‘how long have you been militants?’ We replied that we had never had links with al Shabaab.”

At that point, Somali troops who had previously met the farmers recognized them and told their colleagues to release them, he said. They were told to help collect the dead and injured, he said.

Among the dead were two 13-year-old boys and a 15-year-old, said survivors. Abdi Mohamed, 50, the uncle of one 13-year-old, said his nephew was an orphan working as a shepherd.

Abdi, the uncle of the other, said his nephew was initially only injured but bled to death. Mohamed Osman Aden, the farm owner’s nephew, said the third child was 15.

A clan elder who spoke to Reuters on Friday had given younger ages for the boys.

All three witnesses said no one from the community had fired at the soldiers. Reuters could not independently verify their accounts.

Before the raid, the men had already had four meetings with the soldiers and African Union peacekeepers, said farm owner Ahmed Hassan Sheikh Mohamed. The government wanted the villagers to disarm, but they were reluctant because of their long-standing feud with a rival clan.

Mohamed said the government troops who had driven al Shabaab fighters from the area earlier in August had told the villagers they no longer needed weapons. The villagers put eight guns into storage, but kept one gun in the hands of a watchman, who did not shoot when the soldiers approached.

“Who could fight armored vehicles?” Mohamed asked.

Since the raid, survivors and relatives have been permitted to travel to the capital to make their case, without being arrested as suspected al Shabaab fighters.

PUBLIC ANGER

At the Diplomat hotel in downtown Mogadishu, Somalia’s capital, scores of relatives of the dead occupied every plastic chair, spilling into the corridors and parking lot, sitting on the ground and murmuring angrily.

The bodies were not buried, but were brought to the capital. They are being kept in a refrigerated container taken from a lobster truck and stashed in a nearby garage.

“We do not enjoy keeping the shrinking, wrinkling dead bodies of our brothers and uncles in a fridge for a sixth day. But more painful would be to bury the dead body of your innocent brother as a militant,” said Mohamed Osman Aden, a nephew of one of the dead men.

The refusal to bury a body is a powerful and deeply distressing protest in Muslim culture, which demands that burial take place within 24 hours of death.

The families want blood money - traditionally 100 camels, worth about $100,000, for every dead male. More than that, they want an apology.

“We shall bury them if the government admits they were innocent farmers. If not, we shall keep them in the garage because we never bury militants,” said Aden.

If the clan is not placated, it could rob the government of a powerful ally in the important Shabelle region, site of some of Somalia’s most fertile farmland.

The clan have already been angered by a U.S. airstrike that killed at least 10 members of their pro-government militia last year, and by a death sentence for another clan member who killed a minister that he mistook for a militant.

A split with the government could mean their militia cools relations with Mogadishu at a time when Western allies are trying to bring anti-Shabaab forces closer together.

“The whole problem is the Somali government which brought in and allowed the U.S. to massacre our people,” shouted Halima Mohamed Afrah, the aunt to one of the men killed in Bariire.

“The government should openly say over the media that they killed innocent farmers. Admit it, compensate us and then take the killers to court ... if these conditions are not met ... Blood should be shed for blood.”