The seat of Beichuan county, one of the worst-hit towns in the May 12 quake in China's southwestern Sichuan Province, was closed again early on Thursday for epidemic prevention.
"On the concern of epidemic disease control, the closure will last a long time as the weather is heating up," said Tan Jiamin, the county's public security bureau director.
More than 600 police from Mianyang City have posted "special control" signs and blocked the roads to Beichuan with two check points.
Only police and medical workers with special passes are allowed in.
The hot weather and the large amount of people had brought many difficulties to the prevention work, Tan said.
The remaining bodies had become smelly and attracted many flies and mosquitoes. The place has a lot of people from different professions passing through daily, which puts more pressure on the prevention work, Tan said.
"Some local residents dig for their family members with (bare) hands, which can easily cause infection."
The town would be disinfected daily by military medical workers, Tan said.
Beichuan was sealed off on May 20 for disease control. However, it was reopened several days ago to allow residents fetching their identification cards and possessions.
Many residents had swarmed back to search for their possessions under the debris. Any items removed from Beichuan had to be disinfected and no food was allowed out.
They also went back to commemorate their family members for the last time.
A villager named Lin Yuwang currently living in Anxian County had been going back to Beichuan everyday over the four days. His wife and two-month old daughter were buried in the rubble.
Another memorial ceremony was to happen in a few days, according to local tradition. Lin said he would come back to see them at that time.
"The town is closed. I will hold the ceremony on the top of the mountains," he said.
Many people could bee seen on the top of the mountains, hanging around and reluctant to leave. Some yelled: "Goodbye, Beichuan!"
The small town used to be home to more than 12,000 people, but only half of them survived the quake. All the survivors had been relocated while others rested forever under the rubble, Tan said.
Most of the survivors had been relocated in Leigu and Qushan towns in Beichuan County, while others turned to family members for shelter.
Beichuan has been chosen as the site of a future earthquake museum, for which most parts of the town will be preserved as it is.