Iraqis on Monday mourned the more than 200 people killed by a jihadist-claimed suicide car bombing that was among the deadliest ever attacks in the country.

The blast, which the Islamic State group said it carried out, hit the Karrada district early Sunday as the area was packed with shoppers ahead of this week's holiday marking the end of the Muslim fasting month of Ramadan.

The attack sparked anger among Iraqis at the government's inability to keep them safe even as its forces push IS back, and prompted Prime Minister Haider al-Abadi to announce efforts to address longstanding flaws in Baghdad security measures.

Abadi's office announced three days of national mourning for the victims of the attack and he vowed to "punish" the perpetrators of the blast.

The attack, which security and medical officials told AFP killed at least 213 people and wounded more than 200, came a week after the country's forces recaptured Fallujah from IS, leaving Mosul as the only Iraqi city under the jihadist group's control.

The blast sparked infernos in nearby buildings, and emergency personnel and family and friends of the victims were still searching on Monday for those missing following the explosion.

A member of the civil defence forces said it would take days to recover the bodies of the victims.

Hussein Ali, a 24-year-old former soldier, said six workers at his family's shop were killed, their bodies so badly burned they could not be identified.

"I will return to the battlefront. At least there, I know the enemy so I can fight him. But here, I don't know who I'm fighting," Ali told AFP.

- 'Cowardly and heinous act' -

IS issued a statement claiming responsibility for the suicide bombing, saying it was carried out by an Iraqi as part of "ongoing security operations".

The jihadist group said the blast targeted Iraq's Shiite Muslim majority, whom the Sunni extremists consider heretics and frequently attack in Baghdad and elsewhere.

UN Iraq envoy Jan Kubis condemned the "cowardly and heinous act of unparalleled proportions," calling on authorities to bring those responsible to justice.

Officials said another explosion in the Shaab area of northern Baghdad killed at least one person and wounded four on Sunday, but the cause of the blast was disputed.

Bombings in the capital have decreased since IS overran large areas north and west of Baghdad in June 2014, with the jihadists apparently more concerned with operations elsewhere.

But the group has struck back against Iraqi civilians after suffering military setbacks, and in May, Baghdad was rocked by a series of blasts that killed more than 150 people in seven days.

One video from the scene showed men -- apparently angry at the government's failure to prevent the carnage in Karrada -- throwing rocks at what was said to be Abadi's convoy, while a man could be heard cursing at him in another clip.

But the premier struck a conciliatory tone.

"I understand the emotional feelings and actions that occurred in a moment of sadness and anger," Abadi said in a statement.

With thousands of vehicles moving in and out of the city each day, such bombings are difficult to prevent.

- Security changes -

But there are also flaws in security measures in the city, especially the use of fake bomb detectors at checkpoints years after the man who sold them to Iraq was jailed for fraud in Britain.

Abadi announced a series of changes to security measures following the Sunday bombing, including scrapping the fake detectors.

He also ordered the deployment of scanning devices at entrances to Baghdad to be sped up, directed that security personnel be banned from using mobile phones at checkpoints, and called for increased aerial reconnaissance and coordination among security forces.

Iraqi forces completely recaptured Fallujah, a city 50 kilometres (30 miles) west of Baghdad, from the jihadists a week ago.

Anti-government fighters seized Fallujah in early 2014 and it later became one of IS's main strongholds in the country.

IS's defeat there was compounded by a devastating series of air strikes targeting jihadist forces as they sought to flee the Fallujah area.

Iraqi and US-led coalition aircraft destroyed hundreds of IS vehicles and killed dozens of fighters in two days of strikes against jihadist convoys after the end of the Fallujah battle, officials said.

With Fallujah retaken, Iraqi forces are now setting their sights on second city Mosul, the last major population centre held by IS in Iraq.

Bombings in Iraq so far this year
Baghdad (AFP) July 3, 2016 - A suicide car bombing in Baghdad claimed by the Islamic State group killed at least 75 people on Sunday, in the latest in a long list of deadly attacks in Iraq this year.

The following are some of the bloodiest bombings that have killed hundreds of people since January:

- June -

June 9: Two IS-claimed suicide bomb attacks near the entrance of a military base in Taji, north of Baghdad, and close to a market in the Iraqi capital kill at least 18 people.

- May -

May 17: A series of attacks including suicide bombings claimed by IS kill at least 48 people in Baghdad.

The deadliest bombing hit the frequently targeted Sadr City, a Shiite district in northern Baghdad, killing at least 24.

May 12: At least 16 people are killed when gunmen attack a cafe with gunfire and grenades north of Baghdad then detonate suicide belts against security forces in pursuit.

IS claims the attack on the cafe in the town of Balad popular with fans of Real Madrid football club.

May 11: IS claims three car bombs in Baghdad, including a huge blast at a market in a Shiite area, that kill at least 94 people, in the bloodiest day in the Iraqi capital since the start of the year.

The worst bombing hits Sadr City, killing at least 64 people.

Another suicide car bomb attack kills at least 17 people at the entrance to the northwestern neighbourhood of Kadhimiya, which is home to an important Shiite shrine.

In the Jamiyah district of western Baghdad, another car bomb kills at least 13 people.

May 1: IS carries out rare attacks in mainly Shiite southern Iraq, killing at least 33 people with twin suicide car bomb blasts in the city of Samawa.

- April -

April 30: A car bombing targets Shiite pilgrims in an area near Baghdad, killing at least 23 people.

The bomb is left on a road in the Nahrawan area used by Shiite pilgrims walking to the shrine of an imam in northern Baghdad for annual commemorations.

- March -

March 25: In an attack claimed by IS, a suicide bomber blows himself up during a trophy ceremony after a local football tournament near Iskandiriyah, killing at least 32 people, many of them teenagers and children.

March 6: At least 61 people are killed when a massive truck bomb claimed by IS explodes at a crowded checkpoint at one of the entrances to the city of Hilla.

- February -

February 28: Bombings claimed by the jihadist group kill at least 33 people near a market in the Sadr City area.

- January -

January 11: In two attacks claimed by IS, jihadist gunmen and bombers kill at least 12 people in a busy market area of Baghdad, while a double blast at a cafe claims another 20 lives.

Suicide blasts, gunfights and hostage-taking kill at least 12 people in Baghdad Jadida. And dual bombings kill at least 20 people at the cafe in the town of Muqdadiyah, northeast of Baghdad.