U.S. warns ships to stay out of parts of Red Sea as Houthi rebels vow retaliation for U.S., U.K. strikes

The U.S. Navy on Friday warned American-flagged vessels to steer clear of areas around Yemen in the Red Sea and the Gulf of Aden for the next 72 hours after the U.S. and Britain launched multiple airstrikes targeting Houthi rebels.

The warning in a notice to shippers came as Yemen's Houthis vowed fierce retaliation for the U.S.-led strikes, further raising the prospect of a wider conflict in a region already beset by Israel's war in Gaza.

U.S. military and White House officials said they expected the Houthis to try to strike back. And President Joe Biden warned on Friday that the group could face further strikes.

The U.S.-led bombardment -- launched in response to a recent campaign of drone and missile attacks on commercial ships in the vital Red Sea -- killed at least five people and wounded six, the Houthis said. The U.S. said the strikes, in two waves, took aim at targets in 28 different locations across Houthi-controlled areas of Yemen.

"We will make sure that we respond to the Houthis if they continue this outrageous behavior along with our allies," Biden told reporters during a stop in Emmaus, Pennsylvania.

Asked if he believes the Houthis are a terrorist group, Biden responded, "I think they are." The president in a later exchange with reporters during a stop in Allentown, Pennsylvania, said whether the Houthis are redesignated as such was "irrelevant."

Biden also pushed back against some lawmakers, both Democrats and Republicans, who said he should have sought congressional authorization before carrying out the strikes.

"They're wrong, and I sent up this morning when the strikes occurred exactly what happened," Biden said.

The Pentagon said Defense Secretary Lloyd Austin ordered the military action from the hospital where he is recovering from complications following prostate cancer surgery.

The White House said in November that it was considering redesignating the Houthis as a terrorist organization after they began their targeting of civilian vessels. The administration formally delisted the Houthis as a "foreign terrorist organization" and "specially designated global terrorists" in 2021, undoing a move by President Donald Trump

Lt. Gen.