A U.S. defense official denied an unsubstantiated claim from Yemen’s Houthi rebels early Monday that the group attacked a mobile U.S. Navy landing base in the Gulf of Aden.

Speaking on condition of anonymity to The Associated Press, a U.S. defense official said there was no reported attack on the USS Lewis B. Puller, as Houthi military spokesperson Brig. Gen. Yahya Saree claimed earlier.

The Puller had been stationed in the Arabian Sea as the U.S. has tried to curb Houthi attacks in the Red Sea on commercial vessels, the AP reported.

The Houthis escalated their attacks in recent weeks on ships in the Red Sea, saying they were objecting to Israel’s offensive in Gaza against Hamas. Many of the targets, however, have not been linked to Israel, and the attacks have jeopardized global trade and stability in the region.

The Puller served as a mobile base for the U.S. Navy SEALs who conducted an operation to seize Iranian-made ballistic and cruise missile components believed to be headed for Yemen, the AP reported. That mission led to the disappearance of two Navy SEALs, and they have subsequently been presumed dead.

The Associated Press contributed.