The injured animal, found by tourists on July 1 in the northwest province of Shaanxi, was improving but "doctors still cannot operate on it because of a lack of blood supplies", Xinhua said.

The panda is being fed with milk and a mixture of bamboo leaves and wheat powder, and receiving nutrients intravenously.

"We can't decide the form of medical treatment until it restores more of its physical strength," Ma Qingyi, veterinarian at the provincial rare animal rescue centre, was quoted as saying.

The panda's eyes were "full of vigour", but it was still in critical condition from a fractured skull, broken legs and chest injuries. Its internal organs and nervous system were also damaged.

The panda was found at a scenic spot about 80 km (50 miles) southwest of Xi'an, provincial capital of Shaanxi.

"Experts believe the panda may have sustained the injuries after falling into a river ravine," Xinhua said. "They also believe the animal was sick which contributed to the fall."

At least 1,500 millilitres of panda plasma were needed to operate, said Ma, adding that it was difficult to find matching blood from other pandas.

"Experts are extracting blood plasma a bit at a time from the panda itself. We have already collected 200 ml, but it is far from enough," said Ma.

A census in 2002 showed that there were 1,596 wild giant pandas living across China, mainly in the more than 40 nature reserves in Shaanxi, Sichuan and Gansu provinces.