A suspected case of bird flu has been identified at a commercial poultry premises in Co Tyrone.
The Department of Agriculture, Environment and Rural Affairs (Daera) said disease control measures have been initiated following the case of notifiable highly pathogenic avian influenza (HPAI) near Omagh.
It is understood hundreds of birds will be culled.
Chief veterinary officer (CVO) for Northern Ireland Brian Dooher said he had introduced the measures following the identification of clinical signs and preliminary results provided by the Agri-Food and Biosciences Institute (AFBI).
Agriculture Minister Andrew Muir said: "A suspect case of notifiable avian influenza was reported on Friday October 3 and initial results suggest the presence of notifiable HPAI.
"The CVO has, therefore, taken the decision, as a precautionary measure, to apply appropriate disease control measures, including the humane culling of all poultry on the site and the introduction of temporary control zones (TCZ) to mitigate for onward disease spread.
"This suspect incursion of HPAI is a stark reminder that we cannot afford to be complacent.
"It is imperative that all bird owners - from backyard hobbyists to commercial flock-keepers with thousands of birds - adhere to all biosecurity measures to protect their flocks."
While the Republic of Ireland's Minister for Agriculture Martin Heydon stressed the need for all those with poultry and kept birds to implement the highest standards of biosecurity to protect their flocks from avian influenza.
"It is vital that all poultry holdings are registered with my Department, whether commercial farms or those who have one or two backyard hens.
"It is a legal requirement, and it is also essential to help protect poultry flocks and farmers livelihoods from the impacts which an outbreak of this disease would bring," Mr Heydon said.
Mr Dooher added: "The disease control measures are crucial to limit any potential spread of disease and I appeal to all bird owners - backyard and commercial - to take all necessary steps to protect your flock.
"This includes ensuring continuous excellent levels of biosecurity and reporting any suspect cases of avian flu to Daera immediately.
"Samples from the infected premises have been sent to the national reference laboratory to confirm strain and pathogenicity.
"Should HPAI be officially confirmed, these TCZs will be revoked and replaced with a three-kilometre protection zone (PZ) and 10-kilometre surveillance zone."
Earlier this year, thousands of birds were culled and sanitation actions carried out at premises in Magherafelt in Co Derry and Cookstown, Pomeroy and Stewartstown in Co Tyrone where cases had been confirmed.
Mr Muir later announced an avian influenza prevention zone (AIPZ), which imposed a range of compulsory biosecurity controls on poultry flocks, to address the risk.
The measures were lifted at the end of May.
