After confirming the presence of highly pathogenic avian flu in a flock of chickens, nearly 48,000 birds were killed at a north Alabama farm, state agriculture officials said.

A Marshall County commercial pullet farm — one that raises chicks from hatching until they are ready to produce eggs when they are moved to a laying barn — was placed under quarantine after samples were confirmed positive for HPAI, the Alabama Department of Agriculture & Industries announced Friday.

HPAI is highly contagious to birds but considered low risk to humans and the virus is not considered a threat to food safety, the department said.