US Commandoes have launched a raid in southern Yemen at dawn today that killed 14 al Qaeda militants and 16 civilians.
One US soldier died and three were injured in the raid, the United States military said.
A local Yemeni official reported earlier that the raid left 41 suspected al Qaeda militants and 16 civilians dead, among them eight women and eight children.
"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," General Votel said.
Military authorities said the operation resulted the capture of information "that will likely provide insight into the planning of future terror plots."
Officials said similar operations have produced intelligence on al Qaeda logistics, recruiting and financing efforts.
It is the first US military raid in the country since it descended into civil war nearly two years ago and the first such operation during the Trump administration.
US special forces attempted to rescue an American and a South African hostage held by al Qaeda in another part of the country in December 2014, but the hostages were killed in the subsequent firefight.
The United States conducted dozens of drone strikes throughout Barack Obama's presidency to combat al Qaeda in the Arabian Peninsula, regarded as one of the global militant group's most dangerous branches.