The U.S. military launched an air strike on Tuesday in the mountains of Yemen against a training camp run by al Qaeda in the Arabian Peninsula, killing dozens of its fighters, the Pentagon said.
"This strike deals a blow to AQAP's ability to use Yemen as a base for attacks that threaten U.S. persons, and it demonstrates our commitment to defeating al Qaeda and denying it safe haven," Pentagon spokesman Peter Cook said.
Yemen is a traditional stronghold for al Qaeda's most active branch, which was founded in 2009 by the merger of the Yemeni and Saudi wings of the network founded by Osama bin Laden.
Its plots against Western targets included an attempt to bomb a U.S.-bound airliner in 2009. It also claimed responsibility for an attack on the Charlie Hebdo magazine in Paris that killed 12 last year, although some analysts suspect its role was more inspirational than direct.
Viewed by Western analysts as the most dangerous arm of al Qaeda, AQAP has also expanded during the chaos of Yemen's civil war between Houthi militia and forces loyal to Saudi-backed President Abd-Rabbu Mansour Hadi.
Even so, AQAP has suffered setbacks, including in U.S. strikes, and is facing competition from the new Yemen branch of jihadist group Islamic State group.
Cook said the training camp was being used by more than 70 AQAP militants.
"We continue to assess the results of the operation, but our initial assessment is that dozens of AQAP fighters have been removed from the battlefield," he said.