BAGHDAD - U.S. Deputy Defense Secretary Paul Wolfowitz, a top Pentagon architect of the U.S.-led war on Iraq, was in Baghdad on Friday on an unannounced visit, Reuters said.

A U.S. military spokeswoman in Baghdad said she had no information on Wolfowitz's itinerary and could not say what he would be doing in Iraq.

Wolfowitz is a powerful deputy to Defense Secretary Donald Rumsfeld, who visited Iraq in April, and seen as one of the most hawkish figures in the Bush administration's Iraq policy.

He has said that U.S. forces would remain in Iraq as long as needed, but not one day longer.

U.S. forces have defused at least one explosive device planted on a highway leading to Baghdad's international airport, the scene of several deadly guerrilla attacks, witnesses said on Friday.

Soldiers closed off the road as sappers worked on the bomb placed in a carton on the median under a flyover. A U.S. soldier on site confirmed the find, but the U.S. military spokeswoman declined to comment on the explosives.

The charge was removed later and troops searched the area for other bombs. Some witnesses said at least one other device was found.