A nuclear-powered US submarine capable of carrying ballistic missiles has arrived in Gibraltar amid heightened security around the Rock’s naval base.

The vessel, identified as the USS Alaska (SSBN-732), entered Gibraltar on Sunday afternoon and was met with a significant military presence around the British territory’s South Mole naval area.

According to Europa Sur, a team of Royal Marines had already been deployed to Gibraltar ahead of the sub’s arrival after flying in via the Royal Air Force.

Authorities have since established a 200-metre exclusion zone around the South Mole, which will remain in force until further notice.

The USS Alaska belongs to the Ohio-class fleet operated by the United States Navy – one of the largest and most strategically important submarine classes in the world.

At approximately 171 metres long and with a submerged displacement of nearly 19,000 tonnes, Ohio-class submarines form a key part of America’s nuclear deterrent capabilities.

The fleet includes 14 ballistic missile submarines (SSBNs) and four guided missile submarines (SSGNs).

In their ballistic missile configuration, the submarines can carry up to 24 Trident II D5 nuclear missiles with a range exceeding 7,000 nautical miles.

Some of the submarines in the class have also been converted into guided missile platforms capable of carrying up to 154 Tomahawk cruise missiles for conventional military operations.

The arrival of the USS Alaska reinforce’s Gibraltar’s strategic role as a naval gateway between the Atlantic Ocean and the Mediterranean, particularly amid ongoing NATO operations and rising geopolitical tensions linked to conflicts in the Middle East and Eastern Europe.

Authorities in Gibraltar have not provided details about how long the submarine will remain at the base or the operational purpose behind the visit.