Travellers at two UK airports have been warned to ensure that their electronic gadgets are charged up before they proceed to boarding flights for the US.

Heathrow and Manchester have devised different ways of complying with a new ruling by the US that some foreign airports should put in place enhanced security measures.

It says that passengers must demonstrate that gadgets such as electronic tablets, smartphones and even cameras can be switched on or they will not be allowed on board planes.

It comes amid fears al-Qaeda are planning more sophisticated ways of evading airline security to plant bombs on airlines.

Checks will be carried out at Heathrow at security control and boarding gates. A Manchester Airport spokesman said the checks on whether devices were charged up would only be done by airline staff at departure gates.

The BBC reported that passengers at Heathrow heading to the US with uncharged equipment will be advised to remove them from their hold luggage at check-in, so that they can top up carried-on gadgets.

They will also be offered the chance to put powered-down kit in their luggage from the cargo hold.

It reported that if they still arrive at the security point with a powerless device, they will be directed to a nearby retailer that might be able to provide a recharging cable, and will be told of the location of airport charging points.

Alternatively they can arrange for a company to bag them up and have them shipped to a destination separately.