WARSAW, March 24 (Reuters) - Polish commandos have seen their first action of the Iraq war, with more than 50 troops joining the five-day-old campaign to oust Iraqi President Saddam Hussein, the Defence Ministry said on Monday.

Confirmation came after U.S. Defense Secretary Donald Rumsfeld said on Sunday the main U.S.-British assault force was being actively supported by troops from Australia and Poland.

A Defence Ministry spokesman said "GROM" (Thunder) special forces had joined operations in the Gulf port of Umm Qasr, where resistance by Iraqi forces was continuing. Prime Minister Leszek Miller said no Polish casualties had been taken so far.

"These operations are regarded as highly professional and highly effective. Our soldiers are earning very high marks," Miller told public radio.

Poland, a NATO member whose government has supported the tough U.S. line against Baghdad, has deployed 200 forces to the Gulf region in what it originally said was a supporting, non-combat, role.

Opinion surveys show that most people in this east European country of 38 million do not want Polish troops to take an active part in fighting in Iraq, although a majority has backed an auxiliary role.

Defence ministry spokesman Eugeniusz Mleczak dismissed concerns that the government may have misled the public.

"From the outset it was expected that these soldiers would take part in military action, otherwise there wouldn't have been much point in sending them," Mleczak told Reuters. ((Reporting by Douglas Busvine, editing by Gill Tudor; Reuters Messaging: douglas.busvine.reuters.com@reuters.net; +48 22 653 9718))