Days after fleeing its stronghold of Falluja, Islamic State has claimed responsibility for an attack on a shopping district in central Baghdad which killed at least 115 people, and again exposed the frailty of security efforts to protect Iraqi citizens.

A second bombing took the toll to at least 120, surpassing the most deadly day in the capital so far this year, and rivalling other mass death counts throughout the 12-year insurgency.



Millions of Iraqi children repeatedly and relentlessly targeted, says UN Read more

Isis said it had deliberately targeted Shia Muslims by striking the suburb of Karada, on the southern bank of the Tigris river.

Prime minister Haider al-Abadi announced three days of national mourning for the victims as he visited the site of the attack, and his office said he had vowed to “punish” the perpetrators.

The bombing struck as families and young people were out on the streets after breaking their daylight fast for the holy month of Ramadan late on Saturday evening. Firefighters were still working to extinguish the blazes and bodies were still being recovered from charred buildings as dawn broke on Sunday.

The statement by Isis implied it drew no distinction between civilians and security forces with whom it is battling to retain control of more than a third of the country that it overran in mid-2014, in a rampage that threatened Iraq’s ongoing viability.



Two years later, Isis has lost at least half of that territory and is increasingly resorting to the guerilla tactics that characterised its rise from 2004. Then and now, suicide car bombs, like that used in Karada, have been central to the organisation’s operations.

Baghdad has been struck upwards of 1,000 times, Iraqi officials claim, with the vast majority of those attacks targeting civilian areas frequented by the majority Shia sect, such as market places, shopping strips, religious gatherings and shrines.



Bombings of this scale are less frequent than they were during the darkest years of the sectarian insurgency from 2006-07. However, to many Iraqis, their impact seems all the more shocking at a time when the state military, heavily backed by Shia militias and US-led airstrikes, appears to be prevailing on the battlefield.



The Iraqi prime minister, Haider al-Abadi, has repeatedly assured the country that he will restore security to towns and cities and a semblance of order to the country’s finances, which have been plundered by the industrial-scale corruption of all levels of officialdom.



His efforts to push through a crackdown on corruption have so far failed, but the surprise move to launch an operation to seize Falluja, on the western outskirts of Baghdad, has been hailed as a success, after the last remaining Isis fighters last week fled the city, following close to one month of attacks.



“Isis is attuned to symbolism, and this was in part payback for Falluja,” said an Arab intelligence official based in the region. “They want Abadi to know that they still live among them. And, despite their losses, they haven’t gone anywhere.”



Before the attack, a senior member of Isis told the Guardian that relentless airstrikes in Iraq and Syria had caused serious damage to the organisation and would eventually defeat the group militarily. “The Russians are bombing our families and our areas, but not us,” he said. “The Americans are bombing us and they have good information. The situation is much worse than it was. Morale is not good.”

With the fall of Falluja, Isis has now lost three of the cities it seized in 2014. Mosul, Iraq’s second city, remains the terror group’s last urban stronghold. It also retains influence in Anbar province and has effective control over much of a 500-mile stretch of the border with Syria. However, less than 15% of the country is now thought to be under its control.



In Syria, a US-backed militia, made up mostly of Syrian Kurds allied to the YPG, as well as some Arab fighters, has been trying to cut the road between the second Isis vanguard of Raqqa and al-Bab, which is its westernmost stronghold. The battle to seize Minbij, roughly halfway between the two cities, slowed on Sunday, after Isis counterattacked using car bombs, forcing back the Kurdish-led force.



The Iraqi victory in Falluja appears to have come at less of a cost to the city than similar wins in Ramadi and Tikrit, which saw much of each city destroyed. Refugees from Falluja remain housed in camps in the desert near the city in searing mid-summer temperatures. Officials say many districts of Falluja remain unsafe, due to large numbers of mines and improvised bombs left by Isis as they fled.



Falluja fully liberated from Islamic State Read more

Before the Falluja fight, US officials had been urging Iraq to instead focus energies on seizing Mosul, which is widely regarded as Isis’s centre of gravity. Several efforts by Iraqi troops to push towards Mosul earlier this year had been quickly rebuffed by militants encamped in towns and villages to the south-east of the city.

At least 40 villages must be cleared by Iraqi and Kurdish Peshmerga forces before they reach Mosul from the south-east. The city is also encircled by villages from all other approaches, meaning a path to its centre is likely to be more prolonged and bloody.



However, both US and senior Iraqi officials are optimistic that Falluja will provide a fillip to Iraqi forces gearing up to move on Mosul, some of whom had been shown up in battle as underprepared and lacking in motivation. US planners had been hoping to start the Mosul operation this autumn. Those plans have slipped, but there is a growing belief that an invasion force may be ready by early next year.





