BAGHDAD, Iraq (AP) _ Iraq is challenging the ``no-fly'' zones patrolled by the United States and Britain by flying its warplanes there, Iraq's vice president said today.

The move came a day after U.S. aircraft fired on an Iraqi anti-aircraft battery in the northern ``no-fly'' zone. Iraq says the U.S. attack killed four soldiers and wounded seven others.

Asked if Iraq was flying its own aircraft in the no-fly zones, Ramadan said: ``We are doing it right now.''

``Iraqi planes in effect are flying in a normal manner in Iraqi air space,'' he told Associated Press Television News.

Ramadan also said Iraq will continue firing at any aircraft that violates its airspace. ``Our resistance will continue against any penetration,'' he said. ``The war is still on.''

The United States says its planes fired Monday in self-defense after coming under Iraqi missile attack, while Iraq claims it fired in self-defense after Western warplanes intruded on Iraqi skies.

The United States and its allies set up the ``no-fly'' zones in northern and southern Iraq beginning in 1991 to protect Kurdish and Shiite rebels from Iraqi President Saddam Hussein's forces.