Data compiled by American military authorities in Baghdad show that violence in Iraq is at its highest level since the U.S. invasion in 2003, despite the assassination of al-Qaida leader Abu Musab al-Zarqawi in June.

The New York Times says military commanders provided the data to the newspaper. It shows that the number of roadside bombs planted in Iraq rose in July to the highest monthly total of the war.

The newspaper says the number of daily strikes against American and Iraqi security forces has doubled since January.

It says almost 2,000 bombs exploded in July and that the majority of the bombs were directed at American-led military forces.

While the number of Americans killed in action per month has declined slightly, the newspaper says bomb attacks are now the largest killer of American troops.

A senior Defense Department official told the Times that the insurgency is more capable now and has more public support than at any other point in time.

Recently, American commanders in Iraq shifted thousands of soldiers from outlying provinces to Baghdad to combat increased violence in the capital.

U.S. officials deny that Iraq is in a civil war. But in August, General John Abizaid, the top American military commander in the Middle East, told a congressional committee that Iraq could slide into civil war.