U.S. Gen. David Petraeus said Thursday that insurgents in Iraq have sought to intensify attacks during a Baghdad security crackdown - which he predicted should not be at full strength until June.
Petraeus, the new commander of U.S. forces of Iraq, said the backlash has come since U.S. and Iraqi forces began the security sweep three weeks ago. The Pentagon has pledged 17,500 combat troops to the capital.
Petraeus has said the full contingent should not be in place until early June. He also said additional U.S. forces should head to the Diyala province northeast of Baghdad, but declined to give specifics.
Military officials believe many insurgents have shifted from Baghdad to Diyala to escape the security operation.
"Car bombs have targeted hundreds of Iraqis," Petraeus said in his first news conference since taking over command last month. He also denounced the wave of other attacks, including the "thugs with no soul" who have killed more than 150 Shiite pilgrims in the past three days.
"We share the horror" of witnessing the suicide bombings and shootings against the pilgrims, who are heading for a religious commemoration beginning Friday in the Shiite holy city of Karbala, about 80 kilometers (50 miles) south of Baghdad.
The attacks - mostly blamed on Sunni insurgents - are seen as attempts to provoke a civil war with Shiite militia. But Petraeus said it was "critical" for leaders to halt any drift toward sectarian conflict.
He said U.S. forces are ready to help provide additional security for the pilgrims if asked by Iraqi authorities, the AP says.
"It is an enormous task to protect all of them and there is a point at which if someone is willing to blow up himself ... the problem becomes very, very difficult indeed," he said
But Petraeus added that he saw no role for the powerful Shiite militia known as the Mahdi Army, which had sent out fighters to guard the pilgrimage in the past two years.
He said "extremist elements" in the militia have been engaged in "true excesses" in the past - an apparent reference to suspected gangs carrying out targeted killings against Sunnis.