LONDON — One of the Royal Navy's newest nuclear submarines has collided with a merchant vessel off the coast of Gibraltar.

The collision took place while HMS Ambush was submerged during a training exercise July 20, the Royal Navy said in a statement.

The accident resulted in damage to the front of nuclear attack submarine's conning tower after what the sea service described as a "glancing collision" with a merchant vessel.

The Royal Navy said that there was no damage to the boat's nuclear power plant. The merchant ship showed no signs of damage.

The Astute-class submarine, which has the motto "Hide and Seek," has entered the dockyard at the British overseas territory for further checks.

Ambush was commissioned in 2013 at a cost of around £1.1 billion, or US $1.45 billion. It's the second of what will eventually be seven Astute-class submarines being built for the Royal Navy by BAE Systems.