New cases of the bird flu have been confirmed in western Colorado, and officials will kill 60,000 birds to stop the virus from spreading, the U.S Department of Agriculture announced Wednesday.

The outbreak occurred at a commercial poultry operation in Montrose County.

The National Veterinary Services Laboratory confirmed that birds at a commercial broiler breeder facility had contracted the avian influenza virus (HPAI) H5N1

As of Wednesday, this strain of the bird flu had been reported in 34 states, including Colorado, according to the Department of Agriculture.

Test samples were submitted to the Colorado State University Veterinary Diagnostic Laboratory for preliminary testing and confirmed the virus’ presence on Tuesday, according to a news release.

A quarantine order also has been issued in parts of Montrose and Delta counties to limit the movement of birds out of the area.

“Avian influenza has a high mortality rate and flock owners should actively monitor their birds for clinical signs of HPAI, such as ruffled feathers or swelling and purple discoloration of the comb, wattles, eyelids and legs,” Colorado State Veterinarian Maggie Baldwin said in a news release. “Anyone who notices any signs of illness or disease in their flocks should immediately notify the State Veterinarian’s office at 303-869-9130.”

This is the second confirmed case of the avian flu in Colorado this month. The Department of Agriculture confirmed that a small poultry flock in Pitkin County had contracted the virus on April 8.

Officials are asking poultry owners to increase biosecurity measures to protect their birds from the virus. They are asked to keep a closed flock, decrease interactions between domestic and wild birds and keep feed away from wild birds.