Rescuers of victims of earthquakes in a Tibetan area of western China should be on alert for potential cases of pneumonic plague, state media reported Friday.

Earthquakes in the remote northwestern mountain town of Jiegu have left at least 1,144 people dead, Xinhua said of the confirmed death toll Friday evening.

Wednesday's magnitude-6.9 quake may have awoken marmots from their winter hibernation, China Daily said. The mammals can spread pneumonic plague, which is curable if treated early with antibiotics.

"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," Feng Zijian, from the Chinese Centre of Disease Prevention and Control, told the newspaper.

He also advised rescue workers and survivors of the quake in Yushu county in the province of Qinghai to avoid contact with dead animals to reduce infection risk.

Normally, marmots hibernate until late April or early May, but the animals could surface earlier because of the quake, Feng said.

In August 2008, the World Health Organization said three deadly cases of plague in China were traced to a wild marmot that had contact with the dog of the first patient or index case.

The deaths were attributed largely to delayed treatment, WHO said.

Pneumonic plague occurs when the lungs become infected by the bacterium Yersinia pestis — the same microbe that causes bubonic plague, an infection of the lymphatic system. Pneumonic plague can spread from person to person through the air, according to the U.S. Centers for Disease Control and Prevention.

WHO calls pneumonia plague the most virulent but least common form of plague.

With files from The Associated Press