SHANGHAI (AFP) - A man died during an operation in a Chinese hospital after doctors and nurses fled during a fire, leaving him to suffocate in thick smoke, state media and officials said Friday.

The 49-year-old patient had been in a traffic accident and was having an amputation in the Shanghai hospital on Wednesday when a fire broke out in one of the operating rooms, the official Xinhua news agency said.

Relatives waiting outside the theatre saw six hospital staff, including doctors, nurses and the anaesthetist, flee the room, leaving the unconscious patient, surnamed Zhu, on the operating table.

"We saw smoke coming from the window of the operating room. Then doctors and nurses dashed out. When we asked about the patient, they said he was still inside," Xinhua quoted a witness as saying.

One relative said he later saw Zhu's body on the floor of the operating room but did not see any burn marks.

"The flames did not spread to the room where he was being operated on -- he was apparently suffocated to death," the man surnamed Jin said.

A spokeswoman for the hospital told AFP the doctors and nurses were "being interrogated by fire and police officers so the results of the investigation have yet to come out".

But hospital president Fang Yong told Xinhua the staff were responsible for the man's death.

"We have to say our staff made the wrong judgment, and were not professional enough in providing adequate first-aid," said Fang.

Zhu had been connected to a respirator but "it did not occur to the doctors... that the thick smoke may still suffocate the patient," Fang added.

Fang and the hospital spokeswoman said the fire appeared to have been triggered by an ozone steriliser, which kills germs, in another room.

Nurses tried to extinguish the flames but the fire spread quickly and thick smoke engulfed the operating room.