ZURICH (Reuters) - The Swiss government has vetoed Denmark's request to send Swiss-made armoured personnel carriers to Ukraine, citing its neutrality policy of not supplying arms to conflict zones, Swiss broadcaster SRF reported on Wednesday.

       The State Secretariat for Economic Affairs (SECO) rejected Denmark's bid to provide around 20 Piranha III infantry fighting vehicles to Ukraine, SRF said, citing confirmation from the agency.

       SECO did not immediately respond to a request for comment.

       Neutral Switzerland requires foreign countries that buy Swiss arms to seek permission to re-export them.

       In April it vetoed the re-export of Swiss-made ammunition used in anti-aircraft tanks that Germany is sending to Ukraine. It has also rejected Poland's request for arms to help neighbouring Ukraine.

       Switzerland has parted with past practice and adopted European Union sanctions designed to punish Russia for invading Ukraine, an incursion Moscow describes as a special military operation to disarm and "de-Nazify" Ukraine.

       But Swiss neutrality faces its biggest test in decades as a domestic debate rages over how to interpret the policy that kept Switzerland out of both world wars during the 20th century.

       (Reporting by Michael Shields; Editing by Toby Chopra)