WASHINGTON (AP) _ Two policemen, a female tourist and a suspected gunman were wounded late this afternoon in an exchange of gunfire inside the Capitol at the office of a top Republican lawmaker, officials said.

One man was arrested by a police officer in the office of Rep. Tom DeLay, R-Texas, a spokesman for DeLay said. That officer was wounded, the spokesman said.

The shooting on the first floor of the Capitol building occurred before 4 p.m. EDT, with the House in session and the Senate just finished for the day. The white-domed building was filled with tourists.

``The gunman came into our office and started firing,'' said John Feehery, a spokesman for DeLay. Feehery said he heard about 20 shots.

Feehery said a police officer assigned to protect the office of DeLay, the House's Republican whip, ``did a great job .... in stopping the perpetrator.''

Both the officer who stopped the gunman and the gunman were shot, Feehery said. The congressman, in his office at the time, was not wounded.

Also wounded were a female tourist and another police officer, said Capitol police Sgt. Dan Nichols.