Two new cases of bluetongue disease have been confirmed, Environment Secretary Hilary Benn announced.
The two cases in Peterborough, Cambridgeshire, and Ashford in Kent are within the current bluetongue protection zone which covers much of the south-east and east of England, Defra said.
But they are the first outside the control zone set up around the initial outbreak in East Anglia, where 41 cases had been discovered by Tuesday.
Mr Benn told MPs two new control zones were being introduced and the protection zone was being extended in light of the new bluetongue cases.
Deputy chief vet Fred Landeg said: "This is obviously unwelcome news for the farming industry, however, given the nature of this disease and its means of spread, this is not entirely unexpected.
"We will carry out further investigations on these farms, and in the surrounding area to assess the disease situation and possible sources of incursion.
"Once again, we are grateful for the vigilance of farmers in reporting disease, and urge them to remain vigilant.
"We will continue to work with our core industry group to assess the disease situation and develop the disease control strategy in partnership with the farming industry."
The Environment Secretary told the House of Commons: "As a result of reporting by two farmers in Peterborough and Ashford, Kent, following tests we are confirming two new cases of bluetongue in these locations.
"As a result two new control zones are being introduced and the protection zone is being extended."
