Sporadic clashes are continuing in Mosul, even after Iraq declared a “total victory” over the militant Islamic State (IS) group in the city.

At least one airstrike hit the Old City, the scene of fierce final battles with IS, sending a plume of smoke into the air on Tuesday.

Meanwhile, Amnesty International released a report saying that the conflict in Mosul has created a “civilian catastrophe,” with the extremists carrying out forced displacement, summary killings and the use of human shields.

It called for a commission to investigate crimes against civilians by all sides in the battle to liberate the Iraqi city from jihadists.

“The horrors that the people of Mosul have witnessed and the disregard for human life by all parties to this conflict must not go unpunished,” said Lynn Maalouf, director of Middle East research at Amnesty International.

“An independent commission must immediately be established, tasked with ensuring that any instances where there is credible evidence that violations of international law took place, effective investigations are carried out, and the findings made public,” she added in a statement.

Iraq's Prime Minister Haider al-Abadi declared the “total victory” in Mosul on Monday evening after a nearly nine-month-long battle with IS fighters.

But the victory has left thousands dead and wounded, and the city has been devastated by the fighting since Iraqi forces launched their offensive in October to retake Mosul.

In documenting the conflict between January and mid-May, Amnesty found IS violated international humanitarian law and committed war crimes.

The human rights organisation also criticised Iraqi forces and the US-led coalition, stating they carried out “a series of unlawful attacks” in the city.

Pro-government forces used “imprecise, explosive weapons” in the urban conflict and allegedly used disproportionate force, such as a March 17 attack cited by Amnesty in which 105 civilians died in an air strike targeting two IS snipers.

“Iraqi and coalition forces failed to take adequate measures to protect civilians, instead subjecting them to a terrifying barrage of fire from weapons that should never be used in densely populated civilian areas,” Maalouf said.

Amnesty published a series of recommendations for the Iraqi authorities including establishing a compensation programme for civilians.