The public hospital in Yuen Long reported that an inspection of the cable, which was connected to a computer on a drug-dispensing trolley, showed "unusual damage."

A hospital spokesman said a report from a mixed specialty ward in the early hours of Sunday referred to a nurse being injured by an electric shock while dispensing medication.

The inspection had also shown the trolley's power supply cable had been cut neatly and that the internal copper wire was exposed. The hospital reported the incident to the police and was cooperating with an investigation while taking measures that included inspections of other medication trolleys.

Meanwhile, the injured nurse has been receiving treatment in the hospital for hand paralysis and was in stable condition last night.

Besides the police being alerted the incident was also reported to the Hospital Authority through the advance incident reporting system.

The authority was following up by notifying other hospitals about the circumstances.

Responding to questions from The Standard, police confirmed they had received a report from Pok Oi Hospital staff about the trolley incident and the damaged cable.

But after a preliminary investigation "it was believed the incident does not involve criminal elements. The case is listed as property damage."

Elsewhere, a bedside light unit in a medical ward at Alice Ho Miu Ling Nethersole Hospital in Tai Po broke loose at about 9.30pm on Saturday.

But there were no injuries to patient or staff and the operation of the ward remained normal, a hospital spokesman said.

Engineering staff completed an inspection and repair of the bedside light on Sunday morning and the hospital was investigating the cause of the incident and was inspecting similar installations.