Baghdad: Iraq's prime minister fired three officials in charge of Baghdad's security on Friday after last weekend's bombing that killed nearly 300 people and caused public outrage over the inadequacy of the emergency services and security apparatus.
The bombing, claimed by the ultra-hardline militant group IS, was the deadliest in Iraq since US-led forces toppled Saddam Hussein 13 years ago.
IS has lost ground since last year to US-backed government forces and militias advancing into territories they control in northern and western Iraq, but IS retains the ability to strike the heart of Baghdad.
A statement posted on Prime Minister Haider Al Abadi's Facebook page said he had dismissed the commanders of military operations, security services and intelligence in the capital.
"The sacking of the Baghdad Operations Commander was due to accumulated mistakes that cannot be overlooked," one senior security official said, speaking on condition of anonymity.
"It is a difficult decision and came at a critical time because we are engaged in a tough battle with Daesh (IS), but it had to be made because of the catastrophic failure," he said.
The commander of the Joint Operations Command, General Talib Shaghati Al Kenani, has been put in temporary charge of security in the capital, the security official said. The Joint Operations Command coordinates Iraqi armed forces and US-led coalition air support used in military operations against IS.
The official said the bombing was clear evidence of the weakness of the security apparatus in Baghdad.
"The car bomb came from outside the capital, crossing dozens of checkpoints before reaching the target. All of them answer to the operations command," he said.
Interior Minister Mohammed Ghabban resigned on Tuesday, after blaming the bombing on a lack of communication between the various forces in charge of security in Baghdad.
Abadi approved Ghabban's resignation on the same day he tendered it, according to a statement on the premier's website.
Iraq's top cleric, Grand Ayatollah Ali Al Sistani, on Friday criticised the Abadi government's failure to deal effectively with the threat IS poses.
"Complacency among corrupt and failed (officials) at the expense of the blood and souls of innocent civilians is unbearable and needs to be stopped," he said in his weekly sermon, read on his behalf in Kerbala, south of Baghdad.
IS also claimed a triple suicide attack late on Thursday near a mausoleum north of Baghdad that killed at least 35 people, according to security sources.
Baghdad-based security analyst Hisham Al Hashimi said this attack made an escalation of sectarian strife highly likely.
Prominent cleric Moqtada Al Sadr ordered his militia, the Peace Brigade, to deploy around the mausoleum, near Balad 93km (58 miles) north of Baghdad.
Sadr's militia is also deployed in Samarra. A 2006 bombing destroyed the golden dome of that shrine and set off a wave of sectarian violence.