Related reading:

BAGHDAD, July 3 (Xinhua) -- Up to 126 people were killed and some 152 others wounded in bomb attacks in the Iraqi capital of Baghdad on Sunday, an Interior Ministry source said.

Mourners carry the coffin of their relative, who was killed in a suicide vehicle bomb in the Karrada shopping area in Baghdad, during the funeral in Najaf, south of Baghdad, Iraq, July 3, 2016.

This is the bloodiest attack this year in the country where the army are fighting against the Islamic State militants.

The busy commercial district in southern Baghdad was hit by a car bomb at about 1:00 a.m. local time (2200GMT) when a suicide bomber detonated his explosive-laden pickup truck outside a shopping center.

The three-floor building was completely destroyed, when lots of people were in it. Many of the victims are women and children, the source said.

The powerful blast set fire to the shopping center and four nearby buildings while many shops and stalls were charred and destroyed, along with destroying dozens of civilian vehicles at the scene, the source added.

Dozens of rescue workers, firefighters and civilians were removing debris and burned wreckage from dawn to the evening, looking for survivors and dead bodies.

The attack happened when many families and young people were in the crowded thoroughfare where many shoppers were preparing their families for Eid al-Fitr scheduled to start on Tuesday, which marks the end of the holy month of Ramadan.

Meanwhile, another car bomb went off in a market in northeastern Baghdad, leaving one killed and five wounded, the source added.

The death toll could rise as many wounded are in critical condition.

The bloody bombings have been claimed by the Islamic State group which said that one of its suicide bombers detonated his car bomb at a crowd of Shiite people in the predominantly Shiite district of Karrada-Dakhil, according to a statement posted online, which could not be independently verified.

Iraqi Prime Minister Haider al-Abadi visited the explosion site in Karrada on Sunday morning, vowing to punish those behind the attacks, according to a statement issued by his office.

"The terrorist groups carried out such desperate deadly attack as a result of being crushed in the battlefield," the statement said, referring to the government's recent victory of retaking Fallujah city from IS in the country's western province of Anbar.

Abadi also sent his condolences to the families of the victims and promised that "victory over these terrorist groups is very close."

Local resident Mohammed Musa said:"Now we demand a solution from the government, because since 2003 to 2016 we are uncomfortable, we are in a difficult situation. And those people, all of them lost their money, properties and lives and other things, everything is gone."

The Iraqi government announced victory of retaking Fallujah, one of the last two strongholds of IS in Iraq, late last month, after almost a month of military operations.

The army are expected to by deployed to the northern Nineveh province, preparing to launch attacks against Mosul city, the country's second biggest city that fell into IS control two years ago.

In a statement issued on Sunday, Iraqi President Fuad Masoum condemned the deadly bomb attacks and called on the security forces to "take urgent measures to totally eliminate the sleeper terrorist cells and arrest the perpetrators."

He said "the sleeper terrorist cells are seeking to avenge the defeat of terrorists Daesh (IS group) in Fallujah and other regions of the country."

The IS has frequently targeted the security forces and areas where crowds of people gather, including markets, cafes and mosques across Iraq.

Observers said there could be more attacks against military targets and civilians in the future as the army advance to the last IS stronghold of Mosul

Iraq has been hit by a wave of violence since the IS terrorist group seized large parts in Iraq's northern and western regions since 2014.

A report by UN Assistance Mission for Iraq (UNAMI) estimated that 662 Iraqis were killed and 1,457 others wounded in acts of terrorism, violence and armed conflict in June this year across Iraq.