BAGHDAD (AP) — The Islamic State group on Sunday claimed responsibility for an attack on Iraqi troops outside Karbala that left one dead, according to a statement from the group.

The attack late Saturday came as Iraqi forces prepare an assault on an IS-held town west of Mosul after the country's prime minister declared victory over the extremists in the country's second-largest city in July.

The IS-claimed suicide car bomb attack late Saturday struck a checkpoint outside Karbala and injured two others, according to Iraqi Brig. Gen. Yahya Rasool, spokesman for the Joint Military Command.

The IS statement said the attack targeted a cement factory outside Karbala and resulted in dozens of casualties.

Karbala, some 90 kilometers (55 miles) south of Baghdad, is home to the Imam Hussein Shrine, one of the holiest sites in Shiite Islam.

After nearly nine months of grueling urban combat against IS in Mosul, Iraqi Prime Minister Haider al-Abadi declared victory there in July. The operation deprived IS of their last significant urban foothold in the country.

Now, Iraqi forces closely backed by the U.S.-led coalition are preparing to retake the IS-held town of Tal Afar west of Mosul.

The Islamic State group has launched waves of insurgent style attacks like the Karbala car bombing in the wake of territorial losses in Iraq. As Iraqi forces close in on the handful of IS-held pockets of territory in Iraq, coalition and Iraqi officials have warned that such attacks could increase.

Yousef reported from Cairo.