When it premiered at the Toronto International Film Festival in September, three people reportedly fainted and another suffered a seizure during the screening.

Four months later it appears Oscar-winning director Danny Boyle's latest offering 127 Hours is continuing to provoke such extreme reactions, with at least one cinema in Norwich having to display warning notices after an ambulance had to be called to treat two stricken film-goers.

One person had a seizure and another fainted at Cinema City, in St Andrew's Street, while watching the film's infamous amputation scene during a showing on Saturday night.

The 15 certificate movie, which was released in UK cinemas on Friday, tells the true story of Aron Ralston, a US mountaineer who was forced to cut off his own arm after being trapped under a boulder in a canyon for five days.

Danny Boyle uses computer-generated images to show Mr Ralston, played by James Franco, breaking his own arm and using a blunt penknife to cut through his flesh.

Cinema-goer Jim Rice, 37, who attended the screening on Saturday night with his wife, said the audience had barely reacted to the pivotal scene, but things took a turn just afterwards when it became apparent that someone on the front row had fallen unconscious.

He said: 'We heard someone on the front row trying to rouse the person next to them.

'We saw their head go to one side and at that point people in the cinema realised something had happened.

'Someone called out 'Is there a doctor in the house?' which you never expect to hear.

'And astonishingly, two rows behind us, a guy stood up and said 'Yes I'm a doctor'.

'He put the lady into the recovery position on the floor and monitored her and called for someone to go outside and call an ambulance which they did.

'At that time it became apparent that someone else had also fainted. They sat quite close to us and had become unresponsive and their partner was quite distressed by that.'

The screening had to be cancelled and everyone in the cinema was offered a refund on their ticket.

On the film's grisly scene, Mr Rice said: 'It's not exceptionally gory but the film builds to that moment quite skilfully so there's quite a lot of drama when it actually happens.'

He added praise for the doctor who helped the affected film-goers.

'He was excellent. I didn't catch his name but he totally deserves enormous praise.

'He handled the situation very well running between the two people. I'm sure that's not what he was expecting to do on his evening out.'

A spokesman for Cinema City said one person had fainted and another had had a seizure.

He said: 'They were treated by a GP who happened to be in the screening at the same time.

'One went home and another was taken to A&E as they had a history of illness. Unfortunately it resulted in disruption of the film.

'It's not happened a lot within the Cinema City group but we have had occasional incidents where it has happened with this film.'

He said the cinema was warning customers by displaying signs which outline the British Board of Film Classification's verdict that the film 'contains one scene of strong gory injury and strong language'.

The Vue cinema in Norwich also has notices warning of the film's content.

In a recent interview, Danny Boyle said regular stories of audiences passing out during the film are 'disastrous publicity'.

'It's disastrous publicity for us. Especially for women I think, who are very sensible and would think 'Well why would I want to go to a movie where you faint?''