The aircraft carrier Ark Royal is to leave for the Gulf at the weekend, at the head of a group of Royal Navy vessels.

The Ministry of Defence (MoD) says the group will pass through the region on their way to Malaysia, for a joint naval operation due to take place in June.

But the ships' route will heighten speculation that they are being prepared to take part in possible military action against Iraq.

At the weekend there were reports that Britain was poised to announce the deployment of thousands of troops to the Gulf, to join the build-up of American forces in the area.

Operation Flying Fish

The Ark Royal will leave Portsmouth on Saturday and the flagship vessel will be joined by a submarine, a frigate, a destroyer and two support vessels.

An MoD spokeswoman said the group were taking part in Operation Flying Fish, part of joint naval exercises which take place every three years.

On its way to Malaysia the group is expected to visit at least 25 countries in the Mediterranean, Gulf, Indian Ocean and Pacific.

In September the 20,000-ton Ark Royal was sent to the Mediterranean, which also lead to speculation that it was being readied for war.

US troops

The imminent departure of the Royal Navy groups comes amid growing speculation that Defence Secretary Geoff Hoon is set to announce the deployment of thousands of British troops.

The Daily Telegraph newspaper said the UK was preparing to send 20,000 regular troops and 7,000 reservists to the Gulf.

A spokesman for the MoD said: "We have been making preparations to have credible options available if necessary and we are likely to do more.

"We cannot rule out the possibility of a further statement next week."

The US already has about 60,000 troops stationed in the Gulf with more on the way.