The Swiss hot air balloonist attempting to be the first to fly non-stop around the world has climbed out of his gondola to chip giant icicles off his balloon.

Suspended some 6,000ft above the Sahara desert, psychiatrist Bertrand Piccard broke some of the 10ft spears of ice off with a pickaxe.

Mr Piccard said his skywalk over Mali in west Africa had not been dangerous,

"We felt so safe on the gondola that we didn't even attach our harness. But I must admit the sight of the empty space was very impressive," he said.

Mr Piccard and his British co-pilot, Brian Jones, left Switzerland on Monday, and hope to reach Saudi Arabia by Saturday night.

Balloon race hots up

They are being challenged for the round-the-world record by two British balloonists, Colin Prescot and Andy Elson, who are entering their 17th day in the air on Friday.

The two men, who have already shattered existing distance and endurance records for ballooning, are trying to pick up high winds over Japan that will propel them across the Pacific Ocean at speeds of up to 100mph.

Chinese ban

The British balloonists set off from Spain on 17 January.

But despite their head start, their rivals believe they can outflank them because the Swiss-registered craft has permission to over-fly China.

The British balloon was denied that luxury, because of airspace violations over China by Richard Branson's failed ICO Global Challenger attempt in December which led the Chinese to ban British balloons.

The British balloonist have allowed 25 days - including the lengthy detour - for their flight, compared to Piccard and Jones' optimum 16 days.

There have been approximately 20 previous attempts to fly around the world in a balloon, all of which have failed.