By Michael Bristow
BBC News, Beijing
Thousands of people have been placed in quarantine in north-western China after a man died of pneumonic plague.
Chinese authorities say the man who died was a 32-year-old herdsman from a sparsely populated area mostly inhabited by Tibetans.
Most of the other 11 people infected with the disease are relatives of the dead man.
The local government has not yet said when the man died but it has sealed off the town where the outbreak occurred.
It says there are enough supplies to feed the 10,000 or so people who live in the town of Ziketan, near Xinghai in Qinghai province, during the quarantine period.
Pneumonic plague is a virulent form of the disease that attacks the lungs. It can spread from person to person, or from animals to people.
Initial symptoms include fever, headache and shortness of breath.
To reduce the chances of death, anyone infected needs to receive treatment within 24 hours of the first symptoms.
This is not the only contagious disease that China is grappling with at the moment.
It has taken very strict measures to control the spread of swine flu - which has also led to thousands of people being quarantined.