Sir Ian McKellen has been rushed to hospital after falling off stage during a performance at a London theatre tonight.
The 85-year-old acting legend was involved in a fight scene during a performance of Player Kings at the Noël Coward theatre when he lost his balance and tumbled off the front of the stage.
The audience were evacuated from the theatre in London's West End while medics were called to the venue - and ticket holders have been told the evening show has been cancelled.
It's understood Sir Ian - who plays John Falstaff in the play - was circling a battle scene involving the Prince of Wales and Henry Percy, when he fell off the stage.
As the house lights came up, the Lord of the Rings actor is said to have cried out in pain as ushers rushed to help him.
Audience members, some left in tears, told MailOnline that the star 'was screaming help me' and described the sounds as 'bone-chilling'.
The extent of the actor's injuries are not known at this stage - but at least three London ambulances were pictured outside the theatre.
Player Kings, which started its 12-week West End run in April, is a production of Henry IV, Parts One and Two.
Sir Ian McKellen (centre) bows at the curtain call during the press night performance of 'Player Kings' at the Noel Coward Theatre on April 11
Sir Ian is seen performing in a scene of Player Kings, which is on the West End until June 22
London ambulances are seen rushing to the scene following the shock fall on the West End
Those in the audience have shared their shock at the incident. One tweeted: 'Just witnessed an awful accident with Sir Ian McKellen tripping off the stage in London. He seems badly hurt. We are all in shock and tears.'
Another wrote: 'Audience shocked by Sir Ian McKellen's fall off stage tonight at Noel Coward Theatre. Staff working hard to help him. Thoughts with him, cast and crew.'
And a third said: 'Shocking to watch, it was a terrible fall. Hoping he is not badly injured, he seemed to be in great pain.'
Sandro Trapani told the BBC the incident was 'very shocking', adding: 'I really hope that he is going to be alright. As far as I saw, he was conscious because he was asking for assistance.'
Sir Ian's representatives and the London Ambulance Service have been approached for comment.
Sir Ian, who was born in Burnley, Lancashire, is noted for his work with the Royal Shakespeare Company.
He shot to international acclaim for his film work, receiving an Academy Award nomination in 1998 for Best Actor after he starred in Gods and Monsters. He also played Gandalf in the popular Lord of the Rings films.
In 2019, the actor topped the The Stage 100 list of most influential people in British Theatre following his UK Tour of Ian McKellen on Stage.
Sir Ian was knighted in 1991 for services to theatre and was later appointed a Companion of Honour for services to drama and equality by Queen Elizabeth II in 2008.
Sir Ian McKellen attends the National Youth Theatre's BIG Night Out after party at Soho House Greek Street on June 3
Ian McKellen pictured as Gandalf in The Lord of the Rings: The Return of the King (2003)
Over the past six decades, Sir Ian has taken on the role of almost every Shakespeare male protagonist - but he was 'never attracted to' playing the character of Falstaff until he was persuaded to by director Robert Icke.
After Player Kings' run at the Noel Coward theatre, the show will tour the country. It is due to move to the Bristol Hippodrome in July and will also be staged in Birmingham, Norwich and Newcastle.
The play brings together Shakespeare’s two history plays (Henry IV, parts 1 and 2) with the cast including Toheen Jimoh as Hal and Richard Coyle as King Henry IV.
In April, Sir Ian had to take drastic, and speedy, measures to ensure he made it across London in time for his daily performance on stage – riding on the back of a motorbike.
One source said at the time: 'Sir Ian tried getting picked up by a car provided by theatre bosses but it took so long to get across town it was pointless.
'One night it took him 90 minutes to get from his home. After that, it was decided a motorbike was the only option.'