A man has been arrested after a shooting on board the nuclear submarine HMS Astute left two people injured.
Police were called at 1212 BST to Southampton docks where the vessel has been berthed since Wednesday as part of a five-day visit.
An eyewitness said he saw one person being stretchered off the submarine into a waiting ambulance.
Police said there is no public safety risk and the incident is not linked to terrorism. The area is sealed off.
Brian Cedar, who lives in Hythe marina, said: "I saw at least six people carry a stretcher off the gangway into a waiting ambulance.
"There were a couple of forensic people who have now left.
"If you can have a shooting like this on a nuclear submarine it is worrying."
The area around the docks has been sealed off by officers from Hampshire Police.
The 97m-long (318ft) HMS Astute, the UK's newest and largest nuclear submarine, is based at the Faslane Naval Base on the Clyde.
It ran aground on a shingle bank between the Scottish mainland and the Isle of Skye in October last year and remained marooned for several hours.
HMS Astute was named and launched by the Duchess of Cornwall in June 2007 before being welcomed into the Royal Navy in August last year at a commissioning ceremony at Faslane Naval Base on the Clyde.
The submarine weighs 7,800 tonnes, equivalent to nearly 1,000 double-decker buses, and is almost 100 metres (328ft) long.
Its Spearfish torpedoes and Tomahawk cruise missiles are capable of delivering pinpoint strikes from 2,000km (1,240 miles) with conventional weapons.
The submarine's nuclear reactor means it does not need refuelling and it makes its own air and water, enabling it to circumnavigate the globe without needing to surface.
Reports now say 1 dead and 1 with life threatening injuries.How can there be no risk to the public when there is a shooting on board a nuclear submarine? This is damn serious !
Every comment I have read about the incident in the last 24 hours has had a whiff of scaremongering about it, with most trying to raise worries about a madman launching the boat's nuclear missiles/torpedoes. Well as she is an SSN (hunter killer) and not an SSBN (Bomber), she has no nuclear weapons of any description aboard. The Astute class have the new 'Core H' in their reactors, which will last the design life of the boat (25 years) so refuelling is not needed, and the reactor itself is well sealed and surrounded by thick concrete and steel. Small arms fire isn't going to damage the reactor in any way that would lead to a release of radiation or radioactive material. Everyone needs to calm down about this. It appears to be a 'disgruntled' seaman taking out his frustrations on a couple of officers, for reasons we can only speculate about at this point (and I'm not suggesting we should either) and was neither in the vicinity of or in any way involved the ships reactor.
A tragic incident without a doubt, but not a nuclear incident by any means. I live only three mies from where this incident took place and I'm not packing my bags in readiness to evacuate.
Well not any more. today they have a lot more safety systems and they actually use them. in years gone by however things were not as secure. I saw a documentary recently where they were interviewing a former member of SAC who was one of the minutemen operators. In it he commented that he had watched the movie Dr. Strangelove and had an extra laugh as they did not need a General Jack D Ripper too star World war three, He could have all on his own. As although they were told by the DOD (under Robert McNamara) too install a combination lock on the launcher they were told the code. it was not kept from them an said code did not change it was not until the late 1970's that they actually changed the code on a regular basis and kept it form the missile crews until that time the code consisted of zeroing the lock.You can't expect the uninformed to understand how complicated to actually launch ordinance from a submarine, simply it ain't a one-person job like they'd see in Hollywood movies...in this case, think the sailor's psych review kinda fell through the cracks and thus none saw this coming I believe.