Chinese authorities have warned of a potential outbreak of the deadly pneumonic plague in the aftermath of the quake that left at least 760 dead and thousands hurt, state media reported Friday.

Pneumonic plague is spread by marmots, and health officials fear the 6.9-magnitude earthquake that struck the remote northwest may have woken the large ground squirrels from their winter hibernation, the China Daily said.

"The Ministry of Health has asked all personnel involved in rescue work in the region to keep a close eye and report suspected cases of the plague as soon as they are detected," said Feng Zijian from the Chinese Centre of Disease Prevention and Control.

Marmots usually hibernate in their burrows until late April or early May, but could resurface early due to the impact of Wednesday's earthquake, Feng said.

Rescue workers and survivors of the earthquake in Yushu county in Qinghai province should avoid contact with dead animals to reduce the chance of infection, he said.

An outbreak of the disease last year killed three people in Ziketan, a town in a Tibetan area of Qinghai.

The World Health Organization says pneumonic plague is the most virulent but least common form of plague. The mortality rate can be high, but prompt antibiotic treatment is effective.