First US combat casualty under Trump following Yemen raid
At least 16 Yemeni civilians, an American soldier, and 41 suspected al-Qaeda militants were killed in the raid on Sunday, an official said.
The attack would would be Washington's first military action in Yemen under Trump.
Eight women and eight children were among those killed in the dawn raid in Yakla district, in the central province of Baida, said the provincial official, who did not want to be named, and tribal sources.
But the US military claimed just 14 members of al-Qaeda in the Arabian Peninsula (AQAP), which Washington views as the global network's most dangerous branch, were killed, without mentioning a civilian death toll.
Washington did not specify how the US soldier died. It said three more American servicemen were injured in the raid along with a fourth who was hurt in a "hard landing".
"We are deeply saddened by the loss of one of our elite service members," said General Joseph Votel, commander of US Central Command in Tampa, Florida.
"The sacrifices are very profound in our fight against terrorists who threaten innocent peoples across the globe," Votel said.
Sources in the region said the raid targeted the houses of three tribal chiefs linked to al-Qaeda.
The provincial official said Apache helicopters also struck a school, a mosque and a medical facility which were all used by militants.
Other sources spoke of US commandos taking part in the operation before the White House released the statement.
The three prominent tribal figures killed in the attack were identified as brothers Abdulraouf and Sultan al-Zahab and Saif Alawai al-Jawfi, the official and other sources said.
They were known for their strong links to al-Qaeda, the sources said.
The Zahab brothers have two other al-Qaeda brothers who were also killed in the past by drone strikes.
An al-Qaeda chief in the region, who was identified as foreigner Abu Barazan, was also killed in the attack, the official said.
Among the children killed in the raid was the daughter of the late US-born preacher Anwar al-Awlaqi, Nura, who lived with the family of her maternal uncle, a relative said.
Awlaqi himself was killed in September 2011 in a drone strike and his son Abulrahman was killed two weeks later in a similar attack.
The conflict in Yemen between pro-government forces and Houthi-backed rebels has killed more than 10,000 people since a Saudi-led Arab coalition intervened in 2015.
Agencies contributed to this story.