BAGHDAD (AP) — Iraqi investigators were probing a mass grave on Tuesday that was discovered by troops advancing toward the Islamic State-held city of Mosul.

Here is a look at the main developments on the 22nd day of the Mosul Offensive:

MASS GRAVE

The chilling find was the latest instance of mass graves being uncovered on ground wrested from IS militants. The group has killed thousands of people in both Syria and Iraq.

Footage from the site shows bones and decomposed bodies among scraps of clothing and plastic bags dug out of the ground by a bulldozer in the town of Hamam al-Alil.

The first officials at the site said the grave, behind an earthen embankment near an agricultural college, likely holds about 100 bodies, many of them decapitated. The town lies some 30 kilometers (19 miles) from Mosul. It was unclear who the victims were, but a soldier pulled a child's stuffed animal from the site, which was swarming with flies.

In Geneva, the U.N. human rights office said it was investigating whether the discovery at Hamam al-Alil was connected to reports about the alleged killing of former police officers in the same area.

ADVANCE ON BASHIQA

Kurdish peshmerga forces continued their push on the town of Bashiqa, some 13 kilometers (8 miles) northeast of Mosul. The town is believed to be largely deserted except for dozens of IS fighters.

Mortar fire, automatic weapons, and explosions rang out through the morning, as a thick plume of smoke hung over parts of the city, obscuring the view of aircraft.

U.N. REGISTERS MORE DISPLACED

The United Nations says over 34,000 people have been displaced from Mosul, with about three quarters settled in camps and the rest in host communities.

In a report issued overnight, the U.N. human rights office said the world organization and its humanitarian partners have distributed food, water and medicine to more than 41,000 displaced people and vulnerable residents.

Since the battle for Mosul reached the city itself on Nov. 4, some 11,000 people have fled eastwards, while some electricity and water supplies have been cut in eastern neighborhoods.