At least 50 bodies turned up blindfolded and bound in a predominantly Shiite area south of Baghdad on Wednesday, raising the specter of sectarian war as Iraqi forces, aided by Shiite militias, battle Sunni insurgents across the country.

The bodies, all men ages 20 to 50 who had been shot, were found dumped in the rural district of Khamisiyah, about 60 miles from Baghdad, according to an Iraqi military spokesman and a local journalist who visited the morgue in the nearby town of Hilla where the dead were taken.

Sectarian violence has been on the rise since Sunni militants calling themselves the Islamic State seized control of a vast swath of northern and western Iraq in the past month.

The Islamic State has documented dozens of grisly killings of Shiites with online photos and videos, spurring thousands of Shiite fighters to take to the streets and sparking fears that Iraq could soon see a repeat of the sectarian bloodletting that racked the country in 2006-2007.

It was unclear whether the dead found Wednesday were Sunni or Shiite.

Brig. Gen. Saad Maan, a military spokesman, said no identification documents were found with the bodies, all of which were in civilian garb.

He said that it was not clear how long the bodies had been in Khamisiyah but that they had started decaying in the summer heat.

Maan and the local journalist said the men appeared to have been executed. The journalist, who spoke on the condition of anonymity for fear of reprisal from Shiite militias, said most of the men had gunshot wounds to the head.

She said rumors were circulating in Babil province that the Shiite militia Asaib Ahl al-Haq, which once fought U.S. forces, was behind the killings.

U.S. forces once referred to the rural areas south of Baghdad, and north of where the bodies were found, as the “Triangle of Death.”

“People in Babil believe that these people are Sunnis who had been kidnapped and brought here,” she said of the dead.

Maan said authorities have launched an investigation.

In a sign that Iraq’s divisions are deepening, Prime Minister Nouri al-Maliki accused Kurdish officials Wednesday of harboring Sunni “terrorists” in the country’s north.

“We cannot keep silent about what is happening in Irbil,” Maliki, a Shiite, said in his weekly televised address, referring to the capital of the largely autonomous Kurdish region.

“Irbil is becoming a base for the operations of the Islamic State, the Baathists and the terrorists,” he said, referring to members of Saddam Hussein’s Baath Party.

The predominantly Sunni Kurds have clashed sporadically with Islamic State militants, but they have also been vocal critics of Maliki and want him to step down.

Iraq’s deeply divided political factions are deadlocked in talks to form a new government that they hope will guide the country out of crisis.

Khalid Ali contributed to this report.