Actor Sir Ian McKellen says he is “looking forward to returning to work” after being rushed to hospital after a frightening fall from a London stage.

The 85-year-old actor was reportedly left “screaming in pain” after losing his footing during a fight scene in Player Kings at the Noel Coward Theatre on Monday night, and falling off the stage.

On Tuesday (British time), the Lord of the Rings star took to social media to provide an update for concerned fans.

“I want to thank everyone for their kind messages and support. Since the accident, during a performance of Player Kings last night, my injuries have been diagnosed and treated by a series of experts, specialists and nurses working for the National Health Service,” he wrote on X.

“To them, of course, I am hugely indebted. They have assured me that my recovery will be complete and speedy and I am looking forward to returning to work.”

Sir Ian didn’t offer any further details about his injuries or his recovery time.

Monday’s performance was cancelled after the veteran actor’s accident, which one audience member told the BBC was “very shocking”.

“I really hope that he is going to be all right. As far as I saw, he was conscious because he was asking for assistance,” Sandro Trapani said.

Sir Ian, who plays John Falstaff in the production, was in the midst of a fight scene when the incident occurred. He cried out in pain as staff rushed to help him.

“Just witnessed Ian McKellan severely injure himself after falling off stage at Noel Coward Theatre. Sir Ian could be heard screaming in pain as ushers rushed to his aid. Show cancelled as he is treated by ambulance crews. Wish him all the best,” journalist Charlie Johnson, who was in the threatre audience, posted on X.

Sir Ian previously admitted he was relishing the opportunity to star in the production.

“Actors who have taken on the role say it is verbally very challenging – it seems that the role was written for a particular actor and comedian in Shakespeare’s time, so it’s a bit like being given a script for Michael McIntyre,” he told the BBC earlier this year.

Sir Ian’s career has spanned more than six decades, during which he has performed at theatres across Britain.

On screen he is most known for playing Magneto in the X-Men films and Gandalf in Peter Jackson’s fantasy LOTR trilogy, based on the books from JRR Tolkien.

On the stage he has played a host of Shakespearean characters including Richard II, Macbeth, Coriolanus, and King Lear.

His many acting credits have led to accolades over the years, including several Olivier Awards.

-with AAP