The scaffolding collapsed close to the famous red carpet

The sun screen buckled without warning, possibly because of a gust of wind, security officials have said.

One of the workers was seriously hurt, receiving neck and back injuries. The other men had minor cuts and bruises.

"Everybody just started screaming, saying 'Watch out!' 'Watch out!','' said Harvest Smith, an Oscar production worker who witnessed the collapse.

BBC Liquid News correspondent Stephanie West, who is in Los Angeles covering the Oscars, said she was surprised by the extent of the damage.

"We were surprised at how mangled it looked. It really was a mess of steel.

"Some of the stand was completely upturned, right next to the red carpet."

The ceremony will continue as planned

John Pavlik, spokesman for the Academy of Motion Pictures Arts and Sciences which organises the Oscars, said the ceremony would go ahead as planned.

"No, it will not delay the ceremony at all," he told a press conference.

"We actually were a little bit ahead of schedule today, so we are not terribly concerned about getting back on schedule," he added.

All of the injured men, whose names have not been released, were working on stage constructon and rigging.

BBC Choice's Liquid News will broadcast live from the red carpet at the Shrine Auditorium on Friday evening at 2030 GMT