LONDON (Reuters) - A shipyard in northern England that builds Britain’s new generation of nuclear submarines was evacuated on Wednesday but the atomic safety regulator said there had been no nuclear incident.

FILE PHOTO: A worker walks between the first two Astute class nuclear submarines as they are built in the Devonshire Dock hall at the BAE systems facility in Barrow-in-Furness, northern England, May 8, 2007. REUTERS/Phil Noble (BRITAIN)/File Photo

Ambulances and police were on the scene at the BAE Systems shipyard in Barrow-in-Furness, northwestern England.

“We have been made aware of an incident at the BAE Systems site in Barrow. The incident is not related to nuclear safety,” a spokesman for the Office of Nuclear Regulation said.

“We are liaising with BAE Systems’ site security and will continue to monitor the situation,” the spokesman added.

BAE said the Devonshire Dock Complex at the site had been closed as a precaution.

“Staff, contractors and local residents are being kept informed,” a BAE spokeswoman said.

An unidentified source told The Mail, a Barrow-in-Furness-based publication known previously as the North-West Evening Mail, that staff had been evacuated after a warning about a bomb on an Astute-class nuclear attack submarine.

Barrow-in-Furness makes the new generation of four Dreadnought-class ballistic missile submarines that will eventually replace the Vanguard class vessels which form the basis of the United Kingdom’s Trident nuclear deterrent.

Dreadnought-class submarines will measure 153 metres long, with a displacement of 17,200 tonnes, and have a PWR3 nuclear reactor.

BAE Systems, Rolls Royce and Babcock are the main industrial partners in the 31-billion pound ($41 billion) Dreadnought project.