Security officials warned today of a possible new weapon in the terrorist arsenal – booby-trapped beer coolers.

Law-enforcement officials in the US have been warned to be on the look out for the enticing bombs.

It is feared that an eager beer-lover could find one of the home-made bombs and open it, to an almost certain death.

The warning was sent to 18,000 law-enforcement groups by the FBI last week, Time magazine reported.

People were also warned to be on the look out for booby-trapped plastic-foam containers, inner tubes and other floating objects.

Such objects could be wired to explode if they hit a boat on major waterways, officials told the magazine.

In October 2000 al-Qaida attacked the USS Cole with a suicide boat bomb in a Yemeni port, killing 17 sailors.

Fears of a new terrorist attack were raised in recent weeks after Attorney General John Ashcroft said that al-Qaida was determined to hit the US “hard”.

He cited intelligence, suggesting that major events, such as the July 4 Independence Day celebrations would make an attractive terrorist target.

Despite the latest warning, sources at the FBI and Department of Homeland Security said no floating bombs or booby-trapped beer coolers had actually been found.