Despite the sudden death of a giant panda in an East China zoo last week, such animals living in captivity are well protected, a senior official said, seeking to allay public concerns.

The giant panda Quan Quan cools herself sitting beside an ice block in the Jinan Zoo on June 22, 2008. [China Daily]

"The death was just a single accident and pandas currently under captive breeding and raising are well taken care of," Zhang Hemin, director of the Wolong Nature Reserve Administrative Bureau, said on Tuesday.

The incident occurred on Thursday night in Jinan of East China's Shandong province when the panda, Quan Quan, according to zoo officials there, succumbed to disinfectant gas fumes from a nearby former air-raid shelter.

The episode has since generated public alarm over the conditions in which the endangered species is kept.

The gas was composed of chlorine, chlorine hydride and carbon monoxide, said Liu Jungang, deputy Party secretary of the Jinan Zoo.

Workers were disinfecting the shelter when the gas leaked into the zoo's panda house through an air pipe, Liu said.

Police are continuing their investigation.

The female panda had been on loan to the Jinan Zoo from the Sichuan-based Wolong Giant Panda Reserve Center since September 2007. Aged 21, the panda was the equivalent in age to a 70 year-old person, and had given birth to seven cubs.

The panda's death provoked speculation that the creature died from the negligence and hidden dangers in the panda's room.

Zoo officials declined to release more details.

"I really cannot understand how such accident could have happened. It could have been avoided," Zhang Hemin said.

But Zhang addressed it as an isolated case.

The Wolong Giant Panda Reserve Center now has 156 pandas, but only 77 are currently kept at the center itself.

"A total of 16 pandas are given to foreign countries as gifts and 63 are kept in zoos across the country now," Zhang said.

The rationale behind having the pandas live in different zoos is to help the public heighten their awareness on the need for animal protection, he said.

"People will have a stronger desire to help protect the animals when they see them with their own eyes," Liu said.

The giant pandas are usually sent to big zoos with employees who have considerable experience raising the pandas, according to Liu.

Experts from the center will accompany the pandas and gave guidance to local zookeepers in the first three to six months after the pandas are relocated, he said.

However, Kati Loeffler, a veterinary advisor for the International Fund for Animal Welfare, said that, as with all wildlife, including pandas, the best way to protect them is to keep them in their own habitat.

"It's like living in a jail and everything is limited," she said. "Animals under artificial rearing will lose their natural abilities gradually."

"There should be specific laws in China to protect the welfare of animals that are under artificial rearing", she said, "such as setting down standards on their food, living space and how many animals should be kept together."

All these regulations, she added, "are blank in the country now."