The United States has placed a Navy destroyer off the coast of Yemen to protect waterways from Houthi militia aligned with Iran, two U.S. officials said on Friday, amid heightened tension between Washington and Tehran.

The USS Cole arrived in the vicinity of the Bab al-Mandab Strait off southwestern Yemen where it will carry out patrols including escorting vessels, the officials said, speaking on condition of anonymity.

Earlier this week the armed Houthi movement attacked a Saudi warship off the western coast of Yemen, causing an explosion that killed two crew members.