WARSAW, Poland (AP) — Poland’s agriculture minister says 21 wild boars have died as a result of an outbreak of African swine fever close to the German border.

The minister said Wednesday that the area is being sealed off with a 56-kilometer (34 mile) fence and local hunters have been instructed to eliminate all wild boar in the marked area, near the town of Zielona Gora.

Jan Krzysztof Ardanowski said the disease has not been found in livestock, but that the fence is to protect swine farms in the populous neighboring province around the city of Poznan.

Earlier this year hunters eliminated some 270,000 wild boars in eastern Poland in an effort to prevent the disease from spreading from Ukraine.