Almost 100 people, mostly women and children, died Thursday as a ferry packed with families celebrating Kurdish New Year sank in a swollen river in the former jihadist stronghold of Mosul, in Iraq's worst accident in years.

Explosives left behind by the Islamic State group in Iraq's Mosul took 12-year-old Abdallah's left leg, but another kind of terror may cost him his arm: antibiotic-resistant bacteria.

Amnesty International on Tuesday called for a commission to investigate crimes against civilians in Mosul by all sides in the battle to liberate the Iraqi city from jihadists.

Iraqi forces fought to eliminate the last pockets of Islamic State group resistance in Mosul on Monday after the premier visited the devastated city to congratulate troops on securing victory.

The Iraqi military's hard-fought victory over the Islamic State group in Mosul marks a defining moment not just for them. It is also a key win for the U.S. doctrine behind it.

Instead of putting large numbers of American boots on the ground, the U.S.-led strategy in Iraq and Syria has been a non-stop air campaign combined with continual training and advising for proxy local forces.

Iraqi forces on Thursday battled the last remaining Islamic State group fighters in Mosul's Old City, where the U.N. said up to 20,000 civilians are trapped and in "extreme danger."

Iraqi forces on Monday were searching neighborhoods of west Mosul they retook weeks ago after a surprise jihadist attack on their rear that left several dead, officials said.

Aid workers are preparing for a potentially massive outflow of civilians from Mosul's Old City, the U.N. refugee agency's representative in Iraq said, raising fears for civilians being held as human shields.

Iraqi forces said Tuesday they were fighting fierce battles with the Islamic State group and rescuing escaping civilians as they pursued their offensive against Mosul's jihadist-held Old City.

Iraqi forces pushed deeper into Mosul's Old City on Monday after launching a final assault on the Islamic State group, warning civilians to stay inside and telling jihadists to "surrender or die."