WASHINGTON (Reuters) - Attacks in Iraq last month reached their highest daily average since May 2003, showing a surge in violence as President George W. Bush completed a buildup of U.S. troops, Pentagon statistics show.

The data, obtained by Reuters from the Defense Department, showed an upward trend in daily attacks over the past four months, when U.S. and Iraqi forces were ramping up operations against insurgents and militants, including al Qaeda, in Iraq.