Celebrity magician David Blaine, who spent seven days buried alive last year, has embarked on another chilling endurance test.

Wearing only a hat, light trousers and boots, the 26-year-old entertainer encased himself in a six-ton block of ice in New York's Times Square. He intends to stay there for 58 hours.

The whole icy spectacle is being shown live on the internet.

Tourists stood and gawped as Blaine, a friend of actor Leonardo DiCaprio, said: "This is going to be a lot harder than last year.

"This is going to be tough. At least when I was in the coffin I was lying down."

Blaine's body shape was cut into two blocks of ice which were then welded back together.

'Challenging human fear'

The magician will stand upright, unable to move, and a tube will feed him oxygen and water while electrodes monitor his body's reaction.

"People think I'm crazy, but this is my way of challenging every human fear," he told the New York Post before entering the icy tomb.

Passer-by Peter Marrero, a 22-year-old New Yorker, agreed: "He's nuts, he's crazy.

"He better be getting paid for this."

Blaine has practiced eye signals which he will use to alert a team of doctors, who are on standby in case of problems.

'Danger of blood clots'

His medical consultant, Ronald Rudin, said: "The biggest dangers are loss of circulation and frostbite in his fingers and toes and the threat of falling asleep, in which case his head could slump, bringing his face into contact with the ice.

"There is also the danger of blood clots."

Blaine has been practising for several weeks by immersing himself in tubs of ice for hours and fasting.

The world record for encasement in ice is only 57 minutes but Blaine plans to smash it and make sure it is never reclaimed.

Last year Blaine made headlines after he buried himself for a week in a transparent coffin under tons of water near the Trump Tower in New York.

Nearly 100,000 people came to watch him in his temporary grave.

Blaine is one of the hottest names in magic circles and DiCaprio hosted his recent special show on television.

The latest stunt can be monitored 24 hours a day on his website www.davidblaine.com