The cause of an outbreak of avian influenza suspected on July 10 has been confirmed by the U.K.’s Department for the Environment, Food and Rural Affairs (DEFRA) as the H7N7 subtype.

The case is at an egg farm near Preston in Lancashire in the northwest of England, according to the British Poultry Council. An estimated 170,000 birds have been culled.

A temporary control zone imposed immediately at the affected farm has now been replaced by a 10-kilometer surveillance zone and an inner 3-kilometer protection zone.

“Final tests results have confirmed a case of avian flu at a farm in Lancashire,” said Chief Veterinary Officer Nigel Gibbens. “Restrictions put in place last week will continue and the humane culling of all birds at the site is progressing. These actions are part of our tried and tested approach to dealing with previous outbreaks.

“Public Health England has confirmed that the risk to public health from this strain is very low. The Food Standards Agency has said there is no food safety risk for consumers.

“Bird keepers should remain alert for any signs of disease, report suspect disease to their nearest APHA office immediately and ensure they are maintaining good biosecurity on their premises.”

The last outbreaks of avian flu in poultry were isolated cases in Yorkshire in November 2014 and in Hampshire in February 2015. Both of these were successfully contained.