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 US troops, Pentagon statistics show.
The data from the Defense Department, showed an upward trend in daily attacks over the past four months, when US and Iraqi forces were ramping up operations against insurgents and militants, including al Qaeda, in Iraq.
Pentagon officials were not available to comment on the statistics.
The June numbers showed 5,335 attacks against coalition troops, Iraqi security forces, civilians and infrastructure.
June's total was 2.5 per cent below an October 2006 peak of 5,472 attacks and slightly lower than the 5,365 attacks in May.
But because June has only 30 days, the average daily number of attacks was 177.8, higher than the 176.5 last October and 173.1 in May.
The Pentagon statistics, which come as pressure mounts in the US Congress for a troop withdrawal from Iraq, depicted the most intensive month for daily attacks since Mr Bush declared major combat operations at an end in May 2003.
Daily attacks rose as the Bush administration moved the last combat battalions into place for a security clampdown in Baghdad, part of a controversial U.S. strategy to stabilize Iraq with an additional 28,000 troops.
Mr Bush and other senior officials have predicted that a rise in violence from insurgents and al Qaeda in Iraq would occur this summer as the so-called "surge" strategy takes hold.