North Korea, which has culled tens of thousands of chickens and clamped down on bird movements, may be able to contain its first suspected bird flu outbreaks on three farms, a top U.N. bird flu expert said on Friday.

“For the time being, everything indicates that it can be contained,” Hans Wagner, a senior official with the U.N. Food and Agriculture Organization, told Reuters by telephone from the North Korean capital Pyongyang.

Wagner, in North Korea to assess what is believed to be the first outbreak of Avian Influenza in the secretive nation, said it was not known if the virus was the H5N1 strain that can jump from birds to humans.

H5N1 has killed 49 people since late 2003, sixteen since the disease erupted anew in December, and has proved extremely difficult to stamp out in Thailand, Vietnam and Cambodia.

“There are indications that it is avian influenza, but they lack the diagnostic tools to do a proper diagnosis of which type and sub-type,” said Wagner, who has played a prominent role in Asia’s battle against the deadly H5N1 virus.

The FAO’s China-based regional diagnostic coordinator was expected to fly to Pyongyang on Saturday with testing equipment to confirm the strain of virus, he said.

Officials told Wagner some 219,000 chickens had been culled since the first outbreak was detected on a large poultry farm in Hadang outside the capital. Outbreaks were found on two other farms within a 4-kilometer radius of the first case.

Wagner said authorities have imposed strict controls on animal movements in the area and stepped up surveillance across the country.

“So far there are no indications that we have human flu cases,” he said. “They are very well aware of the general threat of avian influenza on a global scale.”

But Pyongyang’s neighbors are taking no chances.

China has tightened quarantine controls on its border with North Korea, and stepped up the fight against poultry smuggling. South Korea, which has also stepped up quarantine measures at border points and at poultry farms near the border, believes the outbreaks in North Korea are extensive.

The source of the outbreaks was not known, but the fact the three farms are owned by the same company was probably a factor in the spread of the disease.

“Admittedly we are a little bit surprised to have an outbreak in large farms because generally large farms have higher biosecurity standards than smaller farms,” Wagner said.

Most of North Korea’s annual 25 million birds are produced on larger farms, one of the few growing sectors in a country battling severe food shortages.

Bird flu has become entrenched in several other Asian countries because the virus can circulate among small, backyard farms where chickens often mix with wild ducks, believed to be silent carriers of the disease, experts say.