(Erbil) – For nearly three months, Iraqi helicopters came just twice a week to the besieged Shia town of Amerli, dropping food and weapons to the estimated 18,000 residents encircled by Islamic State fighters. Per family, that came to a quarter-cup of rice, three slices of cheese, a handful each of pasta and beans, three tablespoons of tomato paste, and a glass of cooking oil—for families lucky enough to receive their dole.

Accounts by local residents, the mayor, activists  and a doctor coordinating aid efforts whom I reached by phone  provide a glimpse of life during the siege in this farm town 170 kilometers north of Baghdad. Most residents are Turkmen who follow Shia Islam, which the Islamic State considers heresy.

Medicine and gasoline were also scarce. Residents cooked their scant food supplies over fires of cow dung, chairs and sofas.   Islamic State cut  water and power lines, leaving  contaminated well-water and a communications blackout. Each night, they shelled the town with mortar fire—about 2,000 rounds during the 80-day siege by some residents’ count.

“We were living off God’s blessings,” said Basim Ghazi, an Amerli resident. “Families were begging for bread from their neighborhoods.” 

By the time US-backed Iraqi government forces and Shia militia broke the siege on August 31, at least 13 civilians,  including newborn infants, had died from lack of food, water or medical treatment.

The suffering  in Amerli is just a small sample of the crimes taking place in Iraq today.  Islamic State forces have committed acts that amount to crimes against humanity, including executions of hundreds of captives at a time in Tikrit and elsewhere.  Iraqi forces and allied Shia militia have also carried out summary executions and other international law violations that in some cases amount to war crimes.

The United Nations Human Rights Council on September 1 ordered an investigation into Islamic State’s crimes. The inquiry will be critically important, given the inability of Iraq’s tattered and corrupt state to carry out an investigation. It’s equally important for the UN mandate to  include crimes  by the Iraqi forces and their allied militia.

 “The international community must take serious steps to deal with Islamic State crimes and bring those responsible to international justice,” Mayor Adel Albayati of Amerli told me.  The world should heed his call.