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 during the early hours of Saturday 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.
The force was alerted to the incident at 00.40am and arrested the man on suspicion of a public order offence. He remains in police custody.
It is believed the injured patients had been asleep when they were attacked on the general medical ward.
A spokeswoman for Newham University Hospital NHS Trust confirmed that neither drugs nor alcohol were factors in the incident.
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.
