A man is being held by police in connection with an attack at a hospital that left two staff members and five patients injured.

The two female employees received minor injuries as they restrained the 22-year-old man who was being treated at Newham General Hospital in Plaistow, east London. He is thought to have mental health problems.

One of the victims, a woman in her 60s, suffered serious head injuries in the attack but is now in a stable condition, the Metropolitan Police said.

An “improvised weapon” was used to strike the victims, police added.

The three males and one other female patient who were assaulted are in a stable condition at the hospital.

Officers arrested the man on suspicion of a public order offence. He remains in police custody today.

It is believed the injured patients had been asleep when they were attacked on the general medical ward.

A spokeswoman for Newham University Hospital Trust confirmed that neither drugs nor alcohol were factors in the incident.

She said: “Newham University Hospital Trust always places patients and their safety at the centre of our decision making.

“Senior management were on site to manage this incident and are working alongside the Metropolitan Police to help them with their ongoing inquiries.

Acting medical director Frank Chinegwundoh, described the spate of attacks as “freakish”.

Saying it was not unusual for patients to launch attacks on other patients, he said: “In all my 26 years of practising I have not come across another one like it.”

Hospital bosses refused to reveal what the suspect used as a makeshift weapon, but said they did not believe he had brought it into the hospital.

Mr Chinegwundoh would not comment on reports the man launched the attack when he became frustrated over an unanswered request to a nurse for help.

He said: “This is an incredibly uncommon occurrence.

“Security staff are in the hospital but not in every single ward, as is the case in most hospitals.”

Asked if security would be increased because of the attack, he declined to answer but insisted the incident did not happen because of a security lapse.

The suspect was admitted during the last week and was not known by staff to have a psychiatric condition.

“He was not referred to us by a third party,” said the hospital spokesman, but it is believed he was taken to hospital by relatives.

The suspect had not caused any previous disturbances.

Hilary Shanahan, director of nursing and midwifery, said it was too early in the investigation to say if his behaviour was provoked by any medication he was taking for a condition.