The Iraqi government expelled four CNN reporters, including correspondents Nic Robertson and Rym Brahimi, from the country, forcing the four to join the hundreds of U.S. journalists fleeing the bombarded Iraqi capital.

The United States mounted its heaviest air campaign yet in Iraq as ground troops secure some of Iraq's southern territory. Secretary of Defense Donald Rumsfeld and Air Force Gen. Richard Myers, chairman of the Joint Chiefs of Staff, briefed reporters…