"Iraqis are fully aware of the terrorism agenda and will not slip into a sectarian conflict," said Baghdad military command spokesman Col. Dhia al-Wakeel.

But Iraqi authorities have been unable to prevent such wide-scale attacks, even though they were on high alert during a major Shiite pilgrimage. And the number and distribution of these bombings demonstrate the strength and resilience of the Sunni militants.

Altogether, 17 explosions struck Baghdad and six other cities and towns some 300 miles (500 kilometers) apart, from Mosul in the vast deserts of the north to Hillah in the fertile plains of the south. Most targeted Shiite pilgrims between 5 a.m. and 8 a.m. as hundreds of thousands were making their way on foot to the capital.

"I fell on the ground. Then so many people fell on me" said Falah Hassan, who was being treated for wounds at Sheikh Zayid Hospital in Baghdad

Hours after the bombing in Hillah, puddles of blood and shards of metal still clogged a drainage ditch.