U.S. General: Military Alone Won't Win Iraq

BAGHDAD -- Chanting slogans of defiance against insurgents, Shiite pilgrims poured into a holy city south of Baghdad on Thursday amid relentless attacks that have killed more than 170 people this week and left the top U.S. commander in Iraq acknowledging the deadly power of suicide bombers.

"We share the horror [of witnessing the bloodshed]," said U.S. General David Petraeus in his first news conference since taking charge of U.S. forces in Iraq last month.

But Petraeus said security teams were often at the mercy of suicide bombers who have blended into the vast pilgrim processions.

"It is an enormous task to protect all of them," Petraeus told reporters in Baghdad, adding: "If someone is willing to blow up himself ... the problem becomes very, very difficult indeed."

The attacks are part of a wider offensive by suspected Sunni insurgents since a U.S.-led security crackdown began in Baghdad last month.

The Pentagon has pledged 17,500 combat troops for the capital. Petraeus said it was very likely that additional U.S. forces would be sent to areas outside the capital where militant groups are regrouping, including the Diyala province northeast of Baghdad.

The region has become an increasingly important staging ground for groups including al-Qaida in Iraq. Meanwhile, many Sunni extremists apparently have shifted to Diyala to escape the Baghdad clampdown.

Petraeus declined to predict the size of the expected Diyala reinforcements. But he stressed that military force alone was not sufficient to end the violence in Iraq and political talks must eventually include some militant groups now opposing the U.S.-backed government.

"This is critical," said Petraeus, saying such negotiations would "determine in the long run the success of this effort."

One of Iraq's most expansive militias -- the al-Mahdi Army of radical Shiite cleric Moqtada al-Sadr -- appears to have set aside its weapons under intense government pressure .

Al-Mahdi militiamen also have allowed Iraqi authorities to try to protect at least one million pilgrims heading to Karbala, about 80 kilometers south of Baghdad.

Many are making the traditional trek on foot for rituals beginning Friday to mark the end of a 40-day mourning period for Imam Hussein, grandson of the Prophet Mohammed.