The U.S. attacked Houthi weapons sites for the fifth time in one week, this time striking two anti-ship missile sites, the U.S. military said on Thursday.

U.S. surveillance aircraft detected the Houthis preparing missile launchers to attack commercial vessels and Navy ships in the Red Sea, prompting a preemptive operation against the sites, U.S. Central Command (CENTCOM) said in a statement. Since a U.S.-led coalition bombarded missile launchers, weapons depots and radars in Yemen on Jan. 11, the U.S. has conducted several preemptive attacks meant to immediately disrupt planned attacks on international shipping as tensions throughout the region spike.

“As part of ongoing multi-national efforts to protect freedom of navigation and prevent attacks on maritime vessels in the Red Sea, on Jan. 18 U.S. Central Command forces conducted strikes on two Houthi anti-ship missiles that were aimed into the Southern Red Sea and were prepared to launch,” CENTCOM said.

“U.S. forces identified the missiles in Houthi-controlled areas of Yemen at approximately 3:40 p.m. (Sanaa time) and determined they were an imminent threat to merchant vessels and U.S. Navy ships in the region,” the statement said. “U.S. forces subsequently struck and destroyed the missiles in self-defense.”

Wednesday night, U.S. warships and submarines fired Tomahawk missiles on 14 targets in Yemen where the Houthi rebels were preparing missiles to launch further attacks on international shipping, destroying the sites. (RELATED: Navy Reenlistments On US Warship Spiked After Seeing Action Downing Houthi Missiles)

The Pentagon insisted Wednesday that the conflict between Israel and Hamas has not expanded throughout the region as violence escalated following U.S.-led strikes on Houthi positions in Yemen and retaliatory attacks on a U.S.-flagged merchant ship.

“We are going to continue to work with our partners in the region to prevent those attacks or deter those attacks in the future, and we’re also going to continue to work very hard to prevent the Israel Hamas conflict from escalating into a broader regional conflict,” Pentagon press secretary Maj. Gen. Pat Ryder said Wednesday. “We currently assess that the fight between Israel and Hamas continues to remain contained in Gaza,” he added.

A multi-nation operation led by the U.S. launched expansive strikes with aircraft, warships and submarines on munitions depots and launch sites for weapons the Houthis have used to target international shipping in the Red Sea on Jan. 12. More than 150 different types of munitions bombarded more than 60 targets at 28 locations, Pentagon officials have said.

On Wednesday, an explosive-laden drone struck and sparked a fire aboard the Marshall Islands-flagged Genco Picardy, U.S. Central Command (CENTCOM) said, marking the fourth reported incident since the U.S.-led strikes on targets in Yemen.

The Iran- backed group had expanded the scope of targets to include U.S.-owned and operated commercial vessels while already aiming at Israel-linked vessels, according to Reuters.

Today, in response to these continuing threats and attacks, the United States announced the designation of Ansarallah, also known as the Houthis, as a Specially Designated Global Terrorist – Jake Sullivan, U.S. National Security Advisorhttps://t.co/D5d8MylujK pic.twitter.com/pSFUzCR7qk

— U.S. Central Command (@CENTCOM) January 17, 2024

The Houthis have ignored the Biden administration’s repeated warnings against continuing to conduct attacks on international shipping in a critical sea lane, now numbering more than 35 since October, according to the NYT.