WITH machine guns loudly firing off rounds as boats sped past in the darkness, it was like a Hollywood action film come to life.

Worried Nick Tomlinson and his family dived for cover as the frightening firefight unfolded outside their waterside Southampton flat, in case a stray bullet came flying through the window.

The Ocean Village resident was left stunned when he went to investigate what he thought was fireworks disturbing the evening peace, only to see people on boats shooting automatic weapons at each other in the River Itchen.

For about 20 minutes the shots rang out as small vessels whizzed around a larger boat moored on a jetty close to the Itchen Bridge, before it was suddenly all over almost as swiftly as it had begun.

Even police were baffled when Mr Tomlinson called them to find out what had happened.

But last night it was revealed that the on-water gunfight, which the shocked onlooker said looked “just like something out of a James Bond film”, was actually the Royal Marines taking part in a training exercise.

Mr Tomlinson said he was just as stunned with the truth.

He said: “It was like a war zone scene, it was astonishing.

“There were people on boats shooting at each other with what looked like sub-machine guns. It looked like a firefight.

“I could see the flashes from the guns, but the boats were very dark.

“I straight away moved everyone out of the firing line. I was very concerned.

“If it was an exercise it shouldn’t happen so close to homes.

“It’s just a stupid place to do it.”

Police initially had no idea what had happened, but eventually discovered that it had been a military training exercise.

A force spokesman said that they had received no warning of any activity planned in the area.

But a Ministry of Defence spokeswoman said that the Royal Marines had simply been taking part in a standard exercise, and everything was correctly put in place beforehand.

She wouldn’t reveal details of the activity, but said: “It was a routine exercise and all the relevant authorities were informed.

“We told Vessel Traffic Services in advance, and they should then pass that on to the relevant authorities.”