Updated: Submarines collide under Atlantic

Two nuclear-armed submarines, one British and one French, have collided while on separate exercises in the Atlantic Ocean, British newspaper reports said.

The nuclear-powered submarines were badly damaged in the underwater collision earlier this month, the Daily Telegraph said. No one was injured in the accident and there was no damage to the vessels' weapons, the Daily Mirror added.

Neither the British nor the French defence ministries would confirm that the collision had taken place but both issued statements on their nuclear submarine force.

The French defence ministry said Le Triomphant, a nuclear missile submarine, struck a submerged object, which it said was probably a shipping container, while returning from patrol.

It said the vessel suffered damage to its sonar dome, which houses navigation and detection equipment but was able to return to base at L'Ile Longue in Brittany under its own power.

"This incident caused no crew injuries and at no time threatened nuclear security. There has been no interruption to the nuclear deterrent capability," the ministry said in a statement.

The defence ministry in London said it did not comment on submarine operations and would not confirm the reports.

However, in a brief statement, it added: "We can confirm that the UK's deterrent capability has remained unaffected at all times and there has been no compromise to nuclear safety."

The Sun newspaper said modern anti-sonar technology is so good that it is possible that neither submarine detected the other in time.

After the accident in the mid-Atlantic, the Royal Navy's HMS Vanguard returned to base in Faslane, western Scotland, with dents and scrapes visible on its hull, the Sun reported.

Launched in 1992, Vanguard is one of four British submarines that carries the Trident nuclear missile, the country's nuclear defence system. At least one of the submarines is on patrol at all times.

Le Triomphant, which entered service in 1997, carries 16 nuclear missiles and is one of four nuclear-armed submarines in the French fleet.