Patients across Somerset have spoken of the dramatic moment they were forced to evacuate Bristol Royal Infirmary 'in the dark' after a critical incident was declared.

People being treated said they heard what some thought was an 'explosion' as they were plunged into darkness and told to leave the site.

Multiple emergency services were sent to the scene after what hospital bosses have since described as a 'power outage'.

But those forced to flee said there was significant confusion about what was happening - with some claiming it was a ceiling collapse and others saying sparks were flying causing a fire.

Sarah, 56, an office manager from Somerset, said she had been waiting with her sister outside the hospital for more than two hours waiting to see her mother, 88, who has alzheimer’s.

She said "We arrived and they said there’d been a power outage.

"They weren’t giving very much information so it’s just what we’ve heard from people walking past, it seems like it’s quite a lot of fire engines.

"Our mum came into into A&E with a leg wound in the early hours this morning.

"The incident is scary enough. She been through a lot of upheaval over the last few weeks, we thought us being here would be reassuring but we don’t know how long we’ll be out here.

"They said there were no phone lines, but she’s been in there since 3am. We don’t know why she’s inside, and we can’t go in.

"It is worrying because we don’t know to what extent this incident has affected things inside the hospital."

University Hospitals Bristol and Weston NHS Foundation Trust said it was affecting its hospitals in Bristol city centre.

The Trust runs multiple sites in the centre of the city including The Bristol Royal Infirmary (The BRI), Bristol Royal Hospital for Children, St Michael's Hospital and Bristol Eye Hospital.

Interim chief medical officer at UHBW Dr Rebecca Maxwell said: “We have declared a critical incident due to a power outage. We aim to have this fully resolved as soon as possible.

"All patients, visitors and colleagues are safe.

"We ask the public not to attend our Bristol city centre hospitals until the incident is resolved and use alternative services in the area.

"We thank you for your cooperation.”

Avon Fire and Rescue Service said there were currently 10 appliances in attendance outside the hospital.

Avon and Somerset Police have also attended and are managing road closures.