Three patients died and one injured at a mental hospital in central China's Henan Province on Saturday, reported The Paper.

The mental hospital where the incident happened in Luoyang, Henan Province [Photo: thepaper.cn]

The ward's surveillance camera captured the incident.

A patient was tied to his bed by his wrists and ankles, but somehow freed himself, and attacked four other patients in their sleep with a chopstick. Three died and one sustained injuries.

The footage showing the man grabs a chopstick on the table [Photo: thepaper.cn]

Other patients in the ward witnessed the attack and alerted staff, who restrained the patient.

The man who committed the act was diagnosed with severe schizophrenia and has been kept under special supervision since he was hospitalized in February.

The hospital's security measures have fallen under question. The incident happened during a shift swap, and questions have been raised as to how the patient managed to free himself from his bed.

The mental hospital where the incident happened in Luoyang, Henan Province [Photo: thepaper.cn]

The hospital claims the patient's straps were checked several times that day and were confirmed tight.

Relatives of one deceased patient agreed to an 80-thousand-yuan (11.6 thousand USD) amend by the hospital but compensation for the other two deaths remain in question.

The hospital has been shut down and two local health department officials have been dismissed. Police have launched further investigations into the case.