Aug 18, 2008, 11:00 GMT
Britain's Queen Elizabeth's bodyguards are to start patrolling the grounds of her Scottish residence on mountain bikes.
The guards usually drive around Balmoral in Range Rovers - often referred to as 'gaz guzzlers' became they use so much petrol - but officials have decided to swap to push bikes because they are more eco-friendly.
A source told Britain's The Sun newspaper: "Wherever possible the grounds are being patrolled by officers on black mountain bikes.
"They are delighted - they're slashing the fuel bill and getting a good workout as well."
Bodyguards continually roam around the 50,000 acre estate - where the queen traditionally spends her summer - to ensure no intruders break in.
This is not the first time officials have tried to make the estate a more environmentally zone.
The boiler in the main castle runs on wood chips instead of oil and Prince Charles has reportedly experimented with using energy from water from the River Dee to help cut electricity costs.
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