An outbreak of a weak strain of bird flu has been discovered in the Netherlands, prompting Russia and Japan to ban Dutch poultry imports.

The outbreak was discovered during routine tests introduced after last year’s major outbreak in the Netherlands, reported the Associated Press. Last year an outbreak of a highly pathogenic strain of the virus in the Netherlands led to the slaughter of more than 30 million birds, or one-third of the country’s commercial poultry stock.

Japan, which is currently tackling its own outbreaks of bird flu, banned imports of poultry from the Netherlands following reports of the outbreak.

The Russian Agriculture Ministry said it had imposed a similar ban, prohibiting imports of live chickens, eggs and poultry meat from the Netherlands.