Iraqi officials fear there may have been a mass sectarian killing after 50 bodies, many of them found blindfolded and with their hands bound, were discovered on Wednesday south of Baghdad.

Discovered near Hillah, a Shiite-majority city 60 miles south of Baghdad, the bodies had gunshot wounds, military spokesman Brig. Gen. Saad Maan Ibrahim told CBS News. Iraqi officials told Al-Jazeera the men appeared to be killed execution style. The news outlet put the death toll at 53 bodies and said they were found in the village of Khamissiya,

An investigation was launched to identify the victims and the circumstances of their deaths.

The dead bodies were all male, and they ranged in age from 25 to 40. Authorities believe the men were killed somewhere else and their bodies dumped in an agricultural area, a police officer and a medical official told CBS News.

While Hillah and the area where the bodies were found are predominantly Shiite neighborhoods, areas around the town have Sunni majorities. Iraq’s government, led by Prime Minister Nouri al-Maliki, a Shiite, has been accused of marginalizing Sunnis. The Sunni militant group the Islamic State, formerly known as the Islamic State of Iraq and Syria, or ISIS, made large territorial gains in Iraq last month as it carved out a caliphate.

Although there’s no official cause of the deaths of the 50 bodies, their discovery raised concerns that sectarian killings in Iraq, not seen in this magnitude since 2006, have returned. In 2006 and 2007, hundreds of bodies of Sunnis and Shiites were dumped along ditches, canals and the sides of roads.