HRW: ISIL 'Indiscriminately' Attacks Civilians in Mosul

Authorities had earlier said they had retaken Kokjali from the jihadists two months ago.

The group calling itself Islamic State said it was behind three suicide bombings that killed at least 23 people and wounded dozens more outside the Iraqi city of Mosul on Thursday.

ISIS claimed responsibility for the attack in a statement that it posted on Twitter and confirmed that the operations were carried out by three suicide bombers.

"However given that Iraqi forces have not been using artillery in Mosul city, and given that it is likely that the mortar rounds came from probable ISIL held locations, the probability that the mortar rounds were fired by ISIL is high".

"According to initial reports, four aid workers and at least seven civilians queueing for emergency assistance in eastern Mosul city have been killed by indiscriminate mortar fire", Lise Grande, UN humanitarian coordinator in Iraq, said in a statement.

He added that neighbors later informed him that the same strike had killed four IS fighters who had opened fire on Iraqi military forces near his house.

It was the second attack on aid workers and civilians in less than a week.

But the war has taken a significant toll, and commanders have said Islamist militants have offered stiffer resistance than expected, prompting fears that the operation could drag on. "The killing of civilians and aid workers violates every humanitarian principle", she said.

"All parties to the conflict - all parties - have an obligation to uphold worldwide humanitarian law and ensure that civilians survive and receive the assistance they need".

Secretary of Defense Ash Carter visited northern Iraq today, talking up the "historic necessity" of the ongoing military operation aimed to take over the city of Mosul, and expressing confidence that the Iraqi military, backed by United States troops, will eventually prevail. It has become the biggest military operation in Iraq since the 2003 US -led invasion that toppled Saddam Hussein. Iraqi forces pushed deeper into Mosul in November, expanding its foothold in ISIS-stronghold in the country.