It is still unclear how the two assailants wearing suicide vests had entered Baghdad or why they had chosen to attack a market popular for cheap electronics and secondhand clothes.
The first assailant detonated his explosives around 6 a.m., as the sun was rising and as day laborers, shopkeepers and street vendors started gathering for work, according to Maj. Muhammad Mudhir, a traffic police officer who witnessed the attack. Minutes later, as people rushed to help the wounded, the second assailant detonated his explosives, said Kadhim Ali, a construction worker who was at the square.
Dr. Abdul Ghani, the director of Al Rusafa hospital in Baghdad, said at least 27 people had been killed, and 60 others wounded, many of whom were in a serious condition.
Since counterterrorism operations were ramped up in 2015, Iraqi security forces have established a tight security cordon around Baghdad in an attempt to keep insurgents and violence from infiltrating the city.
The belt of suburbs and farms to the west of the capital have long been home to bomb factories for Al Qaeda offshoots that have plagued Iraq since the mid-2000s.
Muhammad al-Jiwebrawi, the head of the Baghdad Province’s security committee, said those areas around the capital remained insecure. He urged the government to increase intelligence operations around the city to flush out insurgents.
“Islamic State terrorists are still present,” Mr. Jiwebrawi said. “There are reasons for what they are doing.”
Although the areas around the capital have been relatively safe compared with previous years, violence has not disappeared.
On Jan. 13, an insurgent detonated an explosive vest near a convoy carrying the head of Baghdad’s provincial government, wounding four Iraqi security forces.
A suicide bombing on a checkpoint in the north of the city on Saturday killed at least five people, according to the Iraqi police.