According to Reuters, the new discoveries bring the total number of confirmed cases to 29 since the first case was identified on 10 September. All of the infections have been in wild boar and all have been in the eastern state of Brandenburg. No farm animals have been infected.

Germany's Friedrich-Loeffler scientific institute has confirmed the latest animals had ASF, the ministry said. The Brandenburg regional government has decided to build a fixed fence to prevent wild boar crossing into Germany from Poland, German federal agriculture minister Julia Kloeckner said, a decision that the federal government had welcomed.

China and a series of other buyers banned imports of German pork this month after the first case was confirmed. Last year China was the main non-EU export market for German pork.

The disease is not dangerous to humans but is fatal to pigs, and a massive outbreak currently ongoing in China, the world's biggest pork producer, has led to hundreds of millions of animals being culled.

Germany had feared a spread of the disease after wild boar in Poland were confirmed only about 10 kilometres from Germany in past months. Several hundred kilometres of temporary cattle fences had been set up along Germany’s border with Poland.

A permanent border fence could make a contribution to preventing the further spread of ASF but there would still be unfenced areas along roads and towns, Kloeckner said.

“A fence can be a foundation for prevention, but no guarantee,” she said.

The agriculture ministry had warned previously that more cases in wild boar are to be expected as the animals move around in groups and the disease is easily transferable.

All dead wild boar in the Brandenburg region are currently being tested for the disease.

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