U.S. B-2 bombers attacked weapons caches belonging to Iran-backed Houthi rebels in Yemen late Wednesday in a strike that appears to be the first such use of the strategic stealth bomber against the militia.

Defense Secretary Lloyd Austin said in a statement the operation was ordered by President Joe Biden to “further degrade” the Houthis’ ability to launch attacks on commercial and military ships in the Red Sea. The strikes could also be a warning to Iran at a time when Tehran and U.S. ally Israel have appeared on the verge of a full-blown war.

Austin did not mention Iran by name. However, he said the use of the B-2 bomber, which is the only warplane in the U.S. arsenal that can carry 30,000-pound so-called bunker busting bombs, “was a unique demonstration of the United States’ ability to target facilities that our adversaries seek to keep out of reach, no matter how deeply buried underground, hardened or fortified. The employment of U.S. Air Force B-2 Spirit long-range stealth bombers demonstrate U.S. global strike capabilities to take action against these targets when necessary, anytime, anywhere.”

The U.S.’s top defense official said the “precision strikes” targeted five “hardened” underground weapons storage locations in Houthi-controlled areas of Yemen. A separate statement from Tampa, Fla.-based U.S. Central Command, or CENTCOM, on Wednesday night said U.S. Navy “assets” also took part in the attack. CENTCOM said it was still assessing “battle damage” but its initial findings “do not indicate civilian casualties.”

The U.S. Air Force describes the B-2 as a “multi-role bomber” capable of delivering conventional and nuclear munitions. It can fly for about 6,000 nautical miles without refueling. Its only operational base is in Missouri.

Iran’s proxies: Houthis in Yemen, Hezbollah in Lebanon, Hamas in Gaza

The Houthis have sporadically attacked ships in the Red Sea commercial waterway, a key trade route, for years. But the attacks, mostly against civilian tankers and cargo ships, have spiked since the start of the latest war between Israel and Hamas last year. The Houthis have said its attacks are in solidarity with Hamas, which is also supported financially and with weapons by Iran, and Palestinians more generally.

Its increased attacks have prompted a growing number of U.S.-led strikes against Houthi targets including radars, runways, missile launch sites and logistics hubs. U.S. forces have also shot down Houthi attack drones and missiles targeted at Israel.

Still, Mohammed Albasha, an independent security analyst who specializes in Yemen, said the U.S. operation with B-2 bombers indicates “a shift in U.S. policy” to a “firmer stance against the group’s destabilizing behavior.”

Yemen specialists say the Houthis are a political movement, a military force and a religious group. They have been fighting in a civil war in Yemen since 2014 against a fledgling government that is backed militarily by Saudi Arabia, the United Arab Emirates and − indirectly, through weapons supplies − the U.S. and Britain.

Albasha said that beyond its maritime aggressions in the Red Sea and attacks on Israel, there are increasing reports of Houthi human rights violations inside Yemen involving aid workers, United Nations staff and international embassy personnel targeted with abductions and forced confessions leading to prosecutions in Houthi “state security courts.” The Houthis, whose leaders seek to emulate and install a strict form of a Shia Islam theocratic system called “Zaydism,” have increasingly restricted women’s freedoms, rights groups say.

The latest Israel-Hamas war in the Gaza Strip, which began a year ago this month when Hamas attacked communities on Israel’s southern border, has mushroomed into a wider regional conflict that has seen Israel attack Iran-backed Hezbollah militants in Lebanon who it accuses of embedding in civilian areas to target northern Israel with missiles.

The latest Israel-Hamas war in the Gaza Strip, which began a year ago this month when Hamas attacked communities on Israel’s southern border, has mushroomed into a wider regional conflict that has seen Israel attack Iran-backed Hezbollah militants in Lebanon who it accuses of embedding in civilian areas to target northern Israel with missiles.

Hezbollah, like Yemen’s Houthis, has said it will keep up its attacks on Israel until there is a cease-fire in Gaza. Lebanon’s health ministry says more than 2,300 people have been killed in Lebanon since last October, three-quarters of them in the past month. The fighting has displaced about 1.2 million people in Lebanon.

The fighting between Israel and groups backed by Iran has threatened to spill over into a larger, direct confrontation between the longtime adversaries after Iran fired a barrage of ballistic missiles at Israel earlier this month. Iran said it was a retaliatory strike for Israel’s killing of Hezbollah leader Hassan Nasrallah and other commanders. Israel has vowed to respond to that attack but it’s not clear exactly how and when and with what force.

Source » usatoday