Residents of a town in northwest China where three people have died from pneumonic plague said Wednesday scared people were trying to leave despite a strict quarantine to contain the virulent disease.
A fourth person was near death in Ziketan, a remote town of 10,000 people in a Tibetan area of Qinghai province, the official Xinhua news agency said.
Another patient was in serious condition and seven others were infected, most of them relatives of the first fatality, a 32-year-old herdsman.
Local authorities have quarantined the town, which is about 200 kilometres (125 miles) southwest of the provincial capital Xining, and its vicinity but some people were trying to flee, residents said.
"Some of my hometown folks left, they are afraid of pneumonic plague," said a businessman who works in the town but hails from neighbouring Sichuan province.
"There are checkpoints in the street and the roads are strictly controlled so they can only leave on foot," the man, who refused to give his name, told AFP by telephone.
"I heard many migrant workers have left, they may go back to their hometowns," he said.
"Those who left without permission lack responsibility. I will not leave."
It was not clear whether any people had managed to breach the quarantine zone, and calls to the local police went unanswered.
Residents said Ziketan resembled a ghost town, with most of the shops shuttered and people staying at home.
"My shop is closed. Most of the shops in the street are closed, especially the supermarket and big shops, leaving just the small vegetable shops," a local vendor told AFP.
"There are few people in the street and people try to avoid going out," he said.
"Some families, including my friends, have left to take refuge, most of them are going back to their hometowns in this county."
Medical staff have been disinfecting the region and tracking down people who have been in close contact with plague patients, Xinhua said.
"In some places, the doctor will enter houses to check" on people, a local businessman told AFP.
"My business is affected, I've had very few clients recently."
Vivian Tan, a spokeswoman for the World Health Organization in Beijing, said there was no real need to stop people leaving the town if steps such as hospitalising patients, tracing their contacts and raising public awareness of what to do with suspected cases were in place.
"As long as these basic measures are taken there really shouldn't be anything stopping people from leaving or from moving freely," she told AFP.
"Ultimately, it's up to the local authorities to take what measures they think are best for the situation," she said in response to reports the town had been quarantined.
Pneumonic plague spreads through the air, making it easier to contract than bubonic plague, which requires that a person is bitten by an infected flea.
The WHO says pneumonic plague is the most virulent but least common form of plague. The mortality rate is high and patients can die 24 hours after infection without treatment with antibiotics.