Sir Ian McKellen, 85, is rushed to hospital after tripping and falling off stage during performance of Player Kings at London's Noel Coward theatre

Sir Ian McKellen has been rushed to hospital after falling off stage during a West End performance in London 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 while medics were called to the venue - and ticket holders were 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 tripped and fell off the stage. 

As the house lights came up, the actor best known for his portrayals of Gandalf in the Lord Of The Rings franchise and Magneto in X-Men, 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'.

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

Images shared on social media showed people holding white boards as the Lord of the Rings star was moved into the ambulance outside the theatre 

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. 

Those in the audience have shared their shock at the incident. 

Paul Critchley, a Methodist minister from Downham Market, Norfolk, said: 'Sir Ian seemed to trip as he moved downstage to take a more active part in the scene.

'He picked up momentum as he moved downstage which resulted in him falling off the stage directly in front of the audience.

'The house lights came up very quickly as the stage management and front of house team dealt with the incident. We were evacuated immediately so that Sir Ian could be treated in privacy.

'An announcement was made by theatre management that the show had been cancelled, that Sir Ian was receiving treatment and an ambulance had been called.

'It was a shock to witness his fall and I wish him a speedy recovery. My thoughts are also with his fellow cast members, stage crew and front of house team at the Noel Coward Theatre.'

Others expressed their horror online. 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.'

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)

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.

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.

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. 

TV star: Sir Ian is shown with Marilyn Tayerson in a still from the 1972 TV show Country Matters

In April, Sir Ian had to take drastic, and speedy, measures to ensure he made it across London in time for his daily performance of the show – 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.'

He has also previously had to pull out of performances due to injuries. In 2018, he had to apologise to theatre-goers after a leg injury forced him to pull out of a performance of King Lear. Sir Ian had been rushing to catch the train and pulled his calf muscle. 

Last September, Sir Ian opened up about his life changing 'overnight' when he came out as gay in 1988.

Marvel villain: The English actor has played Magneto in films based on Marvel Comics and is shown in the 2006 film X-Men: The Last Stand

He told Variety: 'Almost overnight everything in my life changed for the better - my relationships with people and my whole attitude toward acting changed.'

Sir Ian told how coming out actually had a huge impact on his acting work.

He explained: 'The kind of acting that I had been good at was all about disguise - adopting funny voices and odd walks.

'It was about lying to the world. I was no longer in the situation where I was running along beside the character explaining it to the audience. I just became the character.'

Ian also said he felt that it was difficult for non-gay people to relate to his struggle.

The veteran actor said: 'People who are not gay just simply don't know how it damages you to be lying about what you are and ashamed of yourself.

'I was brought up at a time when it was illegal for me to have sex with a man. And that was not that long ago,' he added.

He previously revealed how he had to 'swear he wasn't gay' in order to work on Broadway in the 1960s.

Just last week, Sir Ian made headlines after he took a swipe at former US president Donald Trump - accusing him of being 'one of the worst public speakers there has ever been'.

He told The Times: 'Trump is an absolute bewilderment. I haven't seen him live. But he's one of the worst public speakers there has ever been. Whether he's reading a script or not, it's so patent what he is.'