Dutch authorities were slaughtering thousands of chickens at a poultry farm in central Netherlands after an outbreak of a bird flu variety there, an agriculture ministry spokesman said. "Bird flu has been discovered at a poultry farm with some 47,000 chickens in Creil, in the (central) Flevoland province," Murco Mijnlieff said, adding it was believed to be an H7 low-pathogenic variety. "The farm is being cleaned up and the chickens are being killed," as a result of the outbreak, Mijnlieff told AFP. The outbreak was discovered earlier this week when the farmer noticed a high number of chickens being ill and a lowered egg production. Tests were done, confirming bird flu, Mijnlieff said. Three other farms in the area were being monitored and authorities have introduced a three kilometre (1.8 mile) radius transport ban on poultry, eggs and poultry waste. Mijnlieff said however authorities believed it was a low-pathogenic variety of H7, but more tests were being done with full results expected Saturday. Although a more dangerous variety of high-pathogenic H7 was highly contagious and deadly to chickens, it would cause no more than a slight cold among humans, Mijnlieff said.