Eleven Iraqi state-sponsored fighters were killed early Sunday in an ambush by ISIS insurgents north of the capital, as the extremists ramp up attacks across the country. Authorities said that in addition to the fatalities, 12 members of the Hashed Al Shaabi forces were injured in the attack in the city of Tikrit, in Salah Al Din province. Hashed’s Brigade 22 was the target of the attack, and among those killed was the commander of Hashed’s 3rd Regiment, Hussein Saiedan Kati. "Our security forces will not tolerate terrorism and will continue to pursue ISIS elements in the eastern province of Salah Al Din, as they draw from the strength of our martyrs," Iraqi military spokesman Brig Gen Yehya Rasool said. “ISIS must know that retribution will inevitably come and remorse will not help them.” Brig Gen Rasool said the martyrs' blood will not have been shed in vain. Iraq declared victory over ISIS insurgents in 2017, but has continued to combat the extremists' sleeper cells, mostly found in the desert and mountainous areas. The ambush on security forces comes soon after the group claimed responsibility for an attack in a <a href="https://www.thenationalnews.com/world/mena/baghdad-suicide-bombings-kill-dozens-1.1151018">crowded Baghdad market on Thursday</a>. At least 32 people were killed in the double suicide attack, which was the first large-scale suicide bombing in Iraq for three years. Authorities described the attack as a possible sign that ISIS was becoming more active again. ISIS said two of its insurgents blew themselves up in Tayaran Square, in the centre of the capital, in a statement posted on the group's Telegram communications channel. Suicide attacks used to occur on a daily basis in the Iraqi capital but have halted in recent years, following a gruelling campaign that weakened ISIS. Since then, Baghdad had witnessed an overall improvement in its security situation and a return to normality on its streets. After the Tayaran Square attack, <a href="https://www.thenationalnews.com/world/mena/iraq-fires-security-chiefs-after-baghdad-bombings-1.1151430">Prime Minister Mustafa Al Kadhimi sacked key security and police commanders</a>. Meanwhile, Washington said yesterday that it has allocated $20 million to help Baghdad secure the Green Zone, following rocket attacks on its embassy. The US blames such attacks on Iranian-backed militia groups. Iran has not directly commented on the incidents but little-known groups believed to be connected to the militias have claimed some of the attacks. The Middle East region came close to a full conflict last January, after a US drone strike killed Iran's Maj Gen Suleimani, commander of the Islamic Revolutionary Guard Corps' Quds Force, and Iraqi paramilitary chief Abu Mahdi Al Muhandis at Baghdad Airport. Iran-aligned militias have sworn to avenge their deaths. Late Friday, three rockets were fired on Baghdad Airport, without causing any casualties, the Iraqi military said in a statement. One rocket hit a house in the nearby Al Jihad neighbourhood, the statement said. Iraq, often the scene of spillover violence from US-Iran tensions, seeks to avoid being drawn into any regional conflagration.