Two suicide bombers have blown themselves up at a busy market in central Baghdad in back-to-back explosions that killed at least 38 people, Iraqi officials say.The bombings were the most serious attacks in the capital since the prime minister, Haidar al-Abadi, declared victory over Islamic State a little over a month ago, capping a three-year campaign to reclaim territory from the terror group in Iraq.It raises questions about the government’s readiness to deal with the security challenges posed by the group’s retreat to its insurgent roots, ahead of elections expected in May of this year.The attackers struck during rush hour on Monday morning in Tayran Square, which is usually crowded with labourers seeking work. The explosions wounded at least 105 people, the officials said.The death toll has grown since earlier reports from the health ministry, which said 26 people had been killed, and the interior ministry, which said 16 had died. Both said dozens had been wounded.Ambulances rushed to the scene as security forces sealed off the area. Slippers could be seen scattered about on the blood-stained pavement as cleaners hurried to clear the debris. Photographs posted on social media showed dead bodies and body parts.No group immediately claimed responsibility for the attack but it bore all the hallmarks of Islamic State, which has claimed many such atrocities in the past.There have been significantly fewer large attacks in Baghdad and other parts of country since security forces retook nearly all territory once held by Isis militants.Iraqi and US officials had warned that Isis would continue with insurgent-style attacks even after the Iraqi military and US-led coalition succeeded in ousting the group across the country.The cost of victory has been nearly incalculable as the three-year Isis insurgency devastated much of northern and western Iraq.On Sunday Abadi announced a new political coalition, the Victory Alliance, to contest the upcoming elections. The coalition includes groups close to Tehran.Iran commands great influence in Iraq through proxy militias that have taken part in the campaign against Isis, and which form the core of the Popular Mobilisation Units (PMU), also known as the Hashd al-Shaabi, formed from volunteers after the initial Islamic State advance in 2014.Abadi is credited with leading Iraq and rebuilding the country’s military during three tumultuous years as premier in which the government slowly clawed back cities such as Ramadi, Fallujah, Tikrit and Mosul from Isis.But now he faces great challenges in rebuilding the cities devastated in the military campaigns, ensuring that his government’s policies do not alienate the country’s Sunni minority, and addressing the central authorities’ relationship with the Kurds, who voted overwhelmingly last year for independence from Baghdad in a non-binding referendum.