Air Force B-2 bombers struck five underground weapons facilities in what may be a signal from the Biden administration to Iran.

U.S. military forces hit underground weapons storage facilities in Houthi-controlled areas of north-western areas of Yemen overnight, targeting the Iran-backed group's ability to attack vessels in the Red Sea.

The aircraft was built to slip past defenses to drop nuclear and conventional bombs, including a 30,000-pound bunker buster.

While it wasn't immediately clear how much damage the strikes caused, the attack appeared to be the first use of the B-2 in combat in years.

The bombing is designed to stop the Iran-backed group from attacking commercial and military vessels in the Red Sea and the Gulf of Aden, the Pentagon said.

The US says it has carried out "precision strikes" against five weapons storage locations in areas of Yemen controlled by the Houthi movement. Defence Secretary Lloyd Austin said B-2 Spirit stealth bombers were part of the operation that targeted hardened underground facilities housing missiles and other munitions that the Iran-backed group had used to attack civilian and military ships.

The Pentagon said the U.S. launched airstrikes against Houthi targets in Yemen with B-2 stealth bombers. The strikes targeted five underground weapons facilities. NBC News' Meagan Fitzgerald reports on the first time that the U.