Explosions shook Bahrain early Sunday as Iran’s Revolutionary Guard claimed it targeted a U.S. military base in the Gulf nation, which has faced repeated strikes throughout the ongoing Middle East conflict.

Sirens sounded and authorities posted several alerts on social media urging residents to seek shelter, their first warnings since September.

After a lull in attacks Bahrain, which hosts a major U.S. naval base, has been targeted twice in three days. The energy-rich Gulf has borne the brunt of Iranian strikes during the war.

Bahrain's military said it intercepted several Iranian attacks, "preventing them from reaching their intended targets." The Foreign Ministry said air defense systems shot down Iranian drones.

Explosions could be heard around 4 a.m. (1 a.m. GMT), according to Agence France-Presse (AFP), with residents reporting a second series of blasts around 6:30 a.m.

The Interior Ministry, posting on X, called on "residents to remain calm, proceed to the nearest safe location, and follow news through official channels."

Iran's Revolutionary Guards said their forces carried out a drone attack on a U.S. radar system at a base, according to a statement carried by the Iranian state broadcaster.

"The U.S. air defense radar system at the al-Riffa helicopter base in Bahrain was targeted by six drones belonging to the IRGC Aerospace Force," the Guards said in a statement posted by the state broadcaster on Telegram.

"The Strait of Hormuz is closed and any aggression by the American enemy will be met with an even harsher and more forceful response," it added.

During more than eight months of war, Iran has restricted shipping through the Strait of Hormuz oil trade route and struck infrastructure including airports, seaports, energy facilities, and U.S. assets across the region.

'Settling scores'

Bahrain is among the Gulf countries that have weathered thousands of Iranian drone and missile strikes since the war began on Feb. 28.

The tiny island nation "rejects turning its territory into an arena for settling scores and holds Iran fully responsible for these attacks and their consequences," the Foreign Ministry statement said.

On Friday, the Revolutionary Guards said their forces targeted a U.S. early warning radar system in Bahrain – the first strike against a Gulf country since early September.

The U.S. military's Central Command (CENTCOM) said it shot down two Iranian drones targeting the Gulf island, reporting no casualties or damage in the attack.

CENTCOM, which oversees American military operations in the region, said last month that it had helped Gulf countries export 1.5 billion barrels of oil since the summer via Hormuz.

U.S. President Donald Trump, whose steep reverse in midterm elections was partly blamed on the Iran war, plans to discuss the conflict at a trilateral meeting with his Chinese and Russian counterparts this week, an official said Friday.

Months of diplomacy have failed to resolve the war, which began with surprise U.S.-Israeli strikes that killed Iran's supreme leader Ayatollah Ali Khamenei.