Security at a Birmingham hospital is to be reviewed after a man allegedly threatened staff with a gun and forced them into a store room.

Armed police were sent to City Hospital, in Winson Green, on Wednesday night when a man was reported to have demanded drugs from staff on the gastroenterology ward.  The 24-bed ward was evacuated.

Last night police said a 28 year-old man, who has not been named, had been charged with possession of a imitation firearm and robbery. He will appear before Birmingham Magistrates' Court today.

Some wards at City Hospital are controlled by a swipe-card entry system, and trust bosses will next week discuss whether to extend this facility to all wards.

Although no one was injured, Ann Leedham-Smith, regional director of the Royal College of Nursing (RCN), claimed this had been a "situation waiting to happen" as staff shortages had left nurses in a vulnerable position.

In the last three years there have been several attacks by patients on nursing staff at Midland hospitals.

In January, 78-year-old Ray Rider, of Radford, Coventry, was hit on the head by a fellow patient at the Walsgrave Hospital as he recovered from a hit-and-run accident.

Nurse Helen Kelly was attacked by patient Martin Constable as she worked on the intensive care ward at Wolverhampton's Penn Hospital on May 28, 2004.

Constable, who punched her after learning he would not be released early, left her with two black eyes and a fractured cheekbone.

In November 2004, nurses at the Queen Elizabeth Psychiatric Hospital, in Edgbaston, had to wrestle a gun-wielding patient to the ground to disarm him, while an A&E nurse was hit with an iron bar while on duty at the Alexandra Hospital in Redditch, in August 2003.

Ms Leedham-Smith said: "For the past ten years the RCN has been making representations to the Government for a zero-tolerance policy on violence against staff.

"When I was a nurse we would always check a patient's belongings when they came in, to itemise them so if anything went missing we would not be held responsible.

"There is no way to know how a gun was brought on to the ward, but it's clear that security needs to be stepped up.

"I understand City bosses are looking into their current security arrangements." Pauline Werhun, director of nursing at City Hospital, confirmed a security review was under way.

She said: "Fortunately the staff did get away and called security, who did the right thing in detaining the gentleman in an office.

"During that time other staff on the ward evacuated the ward to make sure it was completely safe. But I think NHS staff do feel vulnerable."