The trial of suspected militants accused of killing hundreds of Iraqi soldiers last year has begun in Baghdad.

The spokesman for Iraq's Supreme Judicial Council, Abdul-Sattar Bayrkdar, told The Associated Press that 28 defendants are being tried for their alleged role in the killing of around 1,700 soldiers when the Islamic State group captured Saddam Hussein's hometown of Tikrit in summer 2015.

Bayrkdar said the defendants acknowledged their participating in the killing of the soldiers who were trying to flee nearby Camp Speicher, an air base on the outskirt of Tikrit.

At the time, the Islamic State group posted graphic images and video that showed its gunmen massacring scores of the soldiers after loading the captives onto flatbed trucks and then forcing them to lay face-down in a shallow ditch.