Bombings in Baghdad killed 26 people and four others died when mortar rounds slammed into their homes in a nearby town Wednesday, the second day of surging violence after authorities lifted a curfew that briefly calmed sectarian attacks.

A spokesman for the powerful Association of Muslim Scholars blasted the Shiite-led government for failing to protect Iraqis, and he urged Sunnis to defend their mosques.

"All evidence has proven that the government and its security forces are incapable of taking any action," said Abdul-Salam al-Kubaisi, a spokesman for the Sunni clerical group.

Al-Kubaisi denied Sunnis were behind the latest attacks, saying Shiite politicians and religious leaders were trying to inflame sectarian hatred "to make use of these events and everything in this country to achieve one goal — to serve their future interests."

Wednesday's most serious attack — a car bomb near a traffic police office in a primarily Shiite neighborhood in southeast Baghdad — killed at least 23 people and wounded 58, according to police Lt. Thaer Mahmoud.

About an hour earlier, a bomb hidden under a car detonated as a police patrol passed near downtown Tahrir Square, said Interior Ministry Maj. Falah al-Mohammedawi. Three civilians died and 15 were wounded.

North of Baghdad, gunmen ambushed a police convoy carrying 50 officers, killing two passengers and abducting 10, police said. Four officers were seriously wounded.

The convoy of five minibuses was returning from a training session in Sulaimaniyah when it was attacked about 45 miles northeast of Tikrit, police Capt. Hakim al-Azzawi said.

The assailants drove off in one of the minibuses.

Mortar shells fell on three houses in the mixed Sunni-Shiite town of Mahmoudiya, 20 miles south of Baghdad, killing three civilians, police Capt. Rashid al-Samaraie said. A fifth mortar shell slammed into the mixed Qadisiyah neighborhood in west Baghdad, killing a woman and wounding a child, Mahmoud said.

Iraq began to tilt seriously toward outright civil war after the Feb. 22 bombing of the revered Shiite Askariya shrine in the mainly Sunni city of Samarra, 60 miles north of Baghdad.

The government said 379 people had been killed and 458 injured as of Tuesday afternoon in nearly a week of sectarian violence tied to the Askariya bombing. Another 30 died Wednesday.

On Tuesday, President Bush said Iraqis must choose "chaos or unity." He said conversations with Iraqi leaders representing Shiite, Sunni and Kurdish factions helped reassure him that no larger role for the U.S. military is required and that the situation will not deteriorate into all-out civil war.

The violence also raised questions about U.S. plans to begin withdrawing troops this summer.

The U.S. military apparently prevented Tuesday's death toll from climbing even higher when soldiers of the 4th Infantry Division discovered a bomb placed near a mosque in Baghdad's Saydiyah neighborhood. There was slight damage to the mosque after a controlled explosion, the military said, adding that civil affairs teams would help with repairs.

On Tuesday, Sunnis and Shiites in Baghdad traded bombings and mortar fire mainly at religious targets, killing at least 68 people. Those attacks came after authorities on Monday lifted curfews and other restrictions.

At least six of Tuesday's attacks hit religious targets. In addition to those known to have been killed Tuesday, police found nine more bullet-riddled bodies, including a Sunni Muslim tribal sheik, off a road southeast of Baghdad. It was unclear when they had died.

Late Tuesday, police reported finding the body of Shiite cleric Hani Hadi handcuffed, blindfolded and shot in the head near a Sunni mosque in Baghdad's notorious Dora neighborhood.