Car bombs killed nearly 170 people in Baghdad on Wednesday in the deadliest attacks in the city since US and Iraqi forces launched a security crackdown aimed at halting the country's slide into sectarian civil war.
One car bomb alone in the mainly Shi'ite Sadriya neighbourhood killed 118 people and wounded 139, police said.
"The street was transformed into a swimming pool of blood," Ahmed Hameed, a shopkeeper near the scene, said.
The apparently coordinated attacks — there were five within a short space of time — occurred hours after Shi'ite Prime Minister Nuri al-Maliki said Iraq would take security control of the whole country from foreign forces by the end of the year.
More than 200 people were wounded in total.
Maliki is under growing pressure to say when US troops will leave, but the attacks in mainly Shi'ite areas of Baghdad underscored the huge security challenges.
"I saw dozens of dead bodies. Some people were burned alive inside minibuses. Nobody could reach them after the explosion," said a Reuters witness at Sadriya, describing scenes of mayhem at an intersection where the bomb exploded near a market.
"There were pieces of flesh all over the place. Women were screaming and shouting for their loved ones who died," said the witness who did not wish to be identified, adding many of the dead were women and children.
One man waving his arms in the air screamed hysterically: "Where's Maliki? Let him come and see what is happening here."
US and Iraqi forces began deploying thousands more troops onto Baghdad's streets in February.
Sectarian death squads killings have declined, but car bombs are much harder to stop, US military officials say.
The bombings could inflame sectarian passions in Baghdad, especially among the Mehdi Army militia of anti-American Shi'ite cleric Moqtada al-Sadr. Sunni Islamist Al-Qaeda is blamed for most of the major bombings targeting Shi'ites in Iraq.
"There is no magic solution to put out the fire of sectarian sedition that some are trying to set up, especially al Qaeda," Maliki said in a speech made on his behalf before the attacks.
"Sunnis are not the enemy of the Shi'ites and Shi'ites are not the enemy of Sunnis."
The Mehdi Army, which numbers in the tens of thousands, has been keeping a low profile since the crackdown began. Washington calls the militia the greatest threat to peace in Iraq.
Sadr withdrew his six ministers from Maliki's cabinet on Monday to press for a pull-out timetable for the 146,000 US troops in Iraq.
Among the other attacks, police said a suicide car bomber killed 35 people at a checkpoint in Sadr City, the stronghold of the firebrand cleric. A third car bomb attack in the capital killed 10 people, police said.
Epicentre of violence
At Sadriya, a thick, dark plume of smoke rose at the scene of the bombing. Fire fighters rushed to put out flames on burning bodies, while rescue workers tried to retrieve bodies from the blackened hulks of cars.
The Sadriya bombing was the highest death toll in a single attack in Baghdad since a truck bomb killed 135 people and wounded 305 in the same area on Feb 3.
Baghdad has been the epicentre of violence in Iraq since suspected Sunni al Qaeda militants blew up a holy Shi'ite shrine in the city of Samarra in February 2006.
In a speech at a ceremony marking the handover of southern Maysan province from British to Iraqi control, Maliki said three provinces in the autonomous Kurdistan region would be next, followed by Kerbala and Wasit provinces.
Then it would be province by province until a full transfer had been completed by the end of the year," Maliki said in the speech, read by National Security Adviser Mowaffaq al-Rubaie.
Maysan is the fourth of Iraq's 18 provinces to be handed to Iraqi security forces, joining Muthanna, Najaf and Dhi Qar, all predominantly Shi'ite and relatively calm regions in the south.
Maliki says Iraq's security forces will only take back control from foreign forces when ready, and he urged patience.
(With additional reporting by Ross Colvin in Amara, Aseel Kami, Ibon Villelabeitia and Yara Bayoumy in Baghdad)