BAGHDAD - Iraqi forensic teams began on Monday excavating 12 suspected mass grave sites thought to hold the corpses of as many as 1,700 soldiers massacred last summer by Islamic State militants as they swept across northern Iraq.
The mass killings last June of Shi'ite soldiers from Camp Speicher, a former US base outside the Sunni city of Tikrit, has become a symbol of the brutality of Islamic State fighters and their hatred for Iraq's Shi'ite majority.
The deaths showed Iraqis that the Islamic State fighters, who have also attacked ethnic and religious minorities as well as fellow Sunni Muslims opposing them, were a threatening new kind of foe.
The images of Shi'ite soldiers being machine-gunned in their hundreds, posted online by the jihadists, could rank as the deadliest single act of bloodshed during a decade of periodic sectarian war in Iraq.
The exhumation of burial sites on the late dictator Saddam Hussein's presidential compound came days after Islamic State militants were driven from the city by Iraqi forces and Shi'ite paramilitaries.
"We dug up the first mass grave site today. Until now we found at least 20 bodies. Initial indications show indisputably that they were from the Speicher victims," said Khalid al-Atbi, an Iraqi health official working with the forensic team sent to Tikrit.
"It was a heartbreaking scene. We couldn't prevent ourselves from breaking down in tears. What savage barbarian could kill 1,700 persons in cold blood?" he asked.