The notice, issued Tuesday on the Agriculture Ministry's Web site, urged enhanced prevention work and timely reporting of bird flu outbreaks in the provinces of Heilongjiang, Jilin, Liaoning, Shandong, Jiangsu and Zhejiang. All are close to South Korea and lie on bird migration routes, the ministry said.

"The six provinces need to step up efforts on surveillance and reporting," the notice said. "If suspected cases are found, they must collect samples and send them to the state bird flu lab in a timely manner."

They also need to have an emergency response system in place if an outbreak occurs, the notice said.

"The measures should include sealing off the area, slaughtering poultry and sterilization," it said.

The South Korean outbreak occurred at a farm in Iksan, about 250 kilometers (155 miles) south of Seoul. Around 6,700 chickens died after being infected with the deadly H5N1 bird flu virus, and another 6,300 were culled.

About 236,000 chickens were also slated for slaughter and 6 million eggs will be destroyed, the South Korean Agriculture Ministry has said. South Korean officials were also planning to kill hundreds of dogs and pigs to try preventing the spread of bird flu.

Since ravaging Asia's poultry in late 2003, the H5N1 virus has killed at least 153 people worldwide. Human infections have been traced to contact with infected birds, but experts fear the virus could mutate into a form that could create a human pandemic.