The illegal movement of animals was continuing, even in areas confirmed with foot-and-mouth disease, the North's Minister of Agriculture, said yesterday.
Ms Brid Rodgers said she was deeply concerned by information that banned movement was occurring within the exclusion zone around Cushendall in Co Antrim, scene of the North's third confirmed case last week.
"There have still been unauthorised movement even in the last few days, as we understand. If this continues to happen our strategy will not work," she said.
Her warning came as two more suspect cases were announced in cattle on a farm in Ardboe, Co Tyrone, and in a flock of sheep in Ballintoy, Co Antrim. Precautionary culls were being carried out at the locations last night.
The suspect cases, with both sets of animals showing clinical signs, have been linked to the two most recent confirmed outbreaks in the North at Ardboe and at Cushendall which brought its total to three cases.
After an Executive meeting at Stormont yesterday, Ms Rodgers said Ministers had agreed to toughen sanctions against those found to be illegally trading or moving animals. "People who are found to have been in breach of the regulations and to have put the whole industry in jeopardy will suffer the consequences," she said.
The Executive also published revised foot-and-mouth guidelines for farmers, the public and visitors to the North.
People are encouraged to visit amenities such as forest and country parks, but should check the venue is open before making the journey. Farmers have been ordered to observe movement regulations and hygiene precautions strictly. They must also stay away from infected areas.
Meanwhile, a spokesman for the Ulster Farmers' Union said yesterday many of its members were unhappy with continued restrictions on moving herds across public roads so as to turn them out to pasture.
From Monday farmers outside restricted areas will be allowed limited movement of animals from shed to grass and from farm to abattoir.
"You would be amazed how many farms have been seriously affected by the restriction to allow animals on to roadways," the spokesman added.
"It is causing a lot of practical difficulties, and we would be looking for a quick solution to this problem from the Minister."