Veterinary officials said the deadly H5N1 virus infected Poland's main poultry region early this month and they voiced fears it might affect about 1 million fowls in the large farms and hundreds of small ones in the Plock region, 60 miles northwest of Warsaw, Polish Radio reported Monday.

No human has been infected, Polish authorities said.

With metric 230,000 tons of poultry exports in 2006, Poland is considered one of major poultry suppliers in the European Union, which last week suspended imports from Poland for 30 days.

Russia, Ukraine, Belarus and Hong Kong were among countries that imposed a ban on poultry imports from Poland.

Police sealed off the Plock region introducing check disinfection points for people and vehicles and banning transport of meat.