North Korea has contained an outbreak of bird flu and the virus was not directly related to a deadly strain that can jump from birds to humans, the United Nations Food and Agriculture Organization (FAO) said Monday.

The FAO said the bird flu outbreak in reclusive North Korea was caused by an H7 strain of the virus, which causes severe disease in chickens but is not directly related to the H5N1 strain circulating in other parts of Asia.

That strain of bird flu has killed 52 people in Cambodia, Vietnam and Thailand and has sparked fears of a global pandemic.

“The virus appears to have been eliminated from the three infected farms by combining culling of 218,000 infected chickens, vaccination of unaffected birds in unaffected poultry houses and strict biosecurity measures,” FAO consultant Les Sims said in a statement released in Rome.

China has tightened quarantine controls at its border with North Korea and barred the entry of poultry to prevent the spread of bird flu.