The Netherlands shuttered petting zoos and banned duck hunting as it stepped up measures Monday to stem a bird flu outbreak blamed for killing scores of poultry and more than a thousand wild birds.

After imposing strict restrictions last week when the first dead birds were found and ordering all poultry farms to keep their flocks inside, the Dutch government on Monday banned visitors to such places.

It has also barred people from petting zoos and told bird-lovers with caged pets at home not to have visitors.

Poultry competitions have been banned as well as bird-hunting, the bureau for economic affairs said in a statement late Monday.

"These extra measures have been taken as a precaution after poultry farms in Hungary, Austria have been widely affected by the avian flu H5N8," a viral strain that unlike H5N1 is not transferable to humans, it said.

Those countries have also ordered the cleaning of bird farms and banned the transportation of the livestock, the Dutch authorities said.

In the western port of Rotterdam, a park closed its animal section after several aquatic birds were found to have died from the virus. Others still not affected have been penned in.

And on the banks of Lake Markermeer, close to Amsterdam, about 1,250 wild birds were found dead last week, according to the RTL news channel. The numbers have been rising in past days, and staff were busy collecting the carcasses on Tuesday.

Switzerland on Tuesday also ordered a ban on free range farming after some dead birds were found around Lake Constance, Lake Geneva and Lake Neuchatel.