HMS Superb was launched by the Royal Navy in 1976
A British nuclear-powered submarine has been damaged after it hit rocks in the Red Sea, defence officials say.
HMS Superb hit an underwater rock on 26 May and damage to its sonar equipment forced it to surface.
No crew members were hurt and the submarine remains watertight, according to a Ministry of Defence spokesman.
He said the submarine's nuclear reactor was "completely unaffected", but a full investigation was under way to determine the cause of the collision.
The 272ft attack vessel had passed through the Suez Canal and was in the northern Red Sea, 80 miles south of Suez itself, when she hit an underwater rock pinnacle.
There were 112 crew on board, but no other vessel was involved.
The MoD said: "There were no casualties and the submarine remains watertight, is safe on the surface and able to operate under her own power."
There was also "no environmental impact" from the collision, he added.
The Navy is now trying to work out how to return the vessel to port.
It is currently in international waters, but is unable to dive because of the damage to its sonar equipment.
HMS Superb was first launched in 1976.