BAGHDAD -- Insurgents foiled heightened security in Baghdad and killed more than two dozen people yester day after an Al Qaeda threat to avenge the death of Abu Musab al-Zarqawi, dealing a blow to the Iraqi government's pledge to bring peace to the capital.
Eleven more Iraqis, including four in Baghdad, died in shooting attacks across Iraq.
US troops, meanwhile, combed through the so-called Triangle of Death, a predominantly Sunni Arab region south of the capital, looking for two soldiers missing since an attack Friday on a traffic checkpoint that also killed one of their comrades.
The spree of bombings and mortar attacks in Baghdad was an embarrassment for Prime Minister Nouri al-Maliki, who ordered more police and army checkpoints for the city last week to restore security for its 5 million residents.
His Sunni Arab deputy prime minister, Salam Zikam Ali al-Zubaie, charged that the plan needed more work.
``I can say that I am not pleased with the way the Baghdad security plan began," he told Al-Jazeera television. ``The Baghdad plan has begun, but it will need a year or more to finish."
Zubaie said the Interior Ministry, which is responsible for Iraq's police forces, has to be cleansed of people who may be responsible for ``human rights violations." Many Sunnis charge that Shi'ite-dominated security services have been infiltrated by Shi'ite militias blamed for sectarian violence.
``There are a lot of officials who were responsible for committing numerous acts of foolishness and many human right violations who are still in positions of responsibility," Zubaie said.
Eight attacks killed at least 27 people and wounded dozens in the Baghdad area.
The violence included a suicide bomber who blew up his car as it was being towed near a police checkpoint in Mahmoudiya, south of the city, killing four civilians and injuring 15. The bomber had claimed his car broke down and hired a tractor to tow it while he rode inside, police Captain Rashid al-Samarie said.
A mortar barrage also hit a residential area in Mahmoudiya, a predominantly Sunni town about 20 miles south of Baghdad, killing a civilian and wounding three.
In Baghdad , a mortar shell hit one of its best-known markets, in the predominantly Shi'ite suburb of Kazimiyah, killing at least four people , police said.
About a half-hour later, two people died when a bomb left in a plastic bag exploded at an outdoor market in central Baghdad.
Police said a suicide bomber targeting an Iraqi Army patrol near Wathiq Square in the same neighborhood killed seven people when he blew himself up.
A bomb-rigged parked car exploded in southwest Baghdad killing six people , police said.
Three mortar rounds hit an open-air market in northern Baghdad, killing two . One other person died from a roadside bombing.
The blasts stepped up a surge of violence that has shattered the fragile calm imposed by the security crackdown launched a week after bombs dropped by a US warplane killed Zarqawi June 7.
On Friday, a suspected shoe bomber targeting a Shi'ite imam who criticized Zarqawi blew himself up inside the Buratha mosque during the main weekly religious service, killing 13 people . The assault was staged during a four-hour driving ban meant to prevent suicide car bombs during Friday prayers. It was the second attack on the Buratha mosque in just over two months. On April 7, four suicide bombers, including a woman, set off their explosives during Friday prayers, killing at least 85 worshi pers. The US military blamed Zarqawi's followers.
Also Friday, Al-Jazeera aired an audio tape of a key insurgency leader calling Zarqawi's death a ``great loss" but saying it would strengthen the militants' resolve.
The broadcaster identified the voice as that of Abu Abdullah Rashid al-Baghdadi, head of the Mujahedeen Shura Council, which groups five Iraqi insurgent organizations, including Al Qaeda in Iraq. The authenticity of the tape could not immediately be verified.
Discussing the missing US soldiers, Major General William Caldwell said raids had been carried out since Friday's attack and that ground forces, helicopters, and airplanes were taking part in the search. The soldiers had come under attack at a traffic checkpoint south of Baghdad. The area is considered an insurgent hotbed.