One man is dead and another is critically injured after a man opened fire on board HMS Astute this afternoon

The navy’s newest nuclear submarine was the scene of a dramatic shooting today which left one man dead and another critically injured.

An air ambulance took the injured man to hospital where his injuries were described as “life threatening”.

The incident is reported to have taken place in the submarine’s control room shortly after midday. Civic dignitaries were being shown around the nuclear-powered boat at the time of the shooting but were not involved. At 12.12pm this afternoon one of the 98-strong crew of the Astute was arrested on board the vessel.

The crewmember is said to have shot two of the crew before being overpowered by others.

First of its class, the Astute is 97-metres long and weighs over 7000 tonnes. The £1 billion submarine was built at BAE Systems Marine Barrow shipyard in Cumbria and launched in 2007. It is usually based in Scotland but was on a five-day visit to Southampton when the shooting occurred.

Hampshire Police who detained the man assure the public that it was not a terror-related incident.

Astute is due to sail on Sunday but her departure may be altered in the light of these events.