More than 30 graves, believed to be of migrants from Myanmar and Bangladesh, were found in southern Thailand on Friday, a media report said, citing officials. The mass grave site was discovered in the Sadao district of Songkhla province at a deserted camp for “boat people,” who had likely been trafficked to Thailand's border with Malaysia, Agence France-Presse reported, noting that the region is infamous for sheltering camps for human-trafficking victims.

Every year, thousands of migrants from Myanmar -- mainly from the Rohingya Muslim minority -- and Bangladesh are brought to Thailand by smugglers. “There are 32 graves. Four bodies have now been exhumed and are on their way ... to hospital to for an autopsy,” Sathit Thamsuwan a rescue worker, told AFP. “The bodies were all decayed.” Thamsuwan also said that a man from Bangladesh survived and was treated at a nearby hospital.

“Military and border patrol police have now cordoned the area off so we can bring forensic officials to the site,” a senior official from Sadao, a small town on the border with Malaysia in Songkhla, told AFP, confirming the discovery of the graves.

A police official told Reuters that four bodies have been exhumed so far from the graves, which were found in a “well set up” smuggling camp. The official also said that rescue workers found two other bodies that had not been buried and were left to rot in the open.

In March, Thailand’s national assembly passed amendments to anti-trafficking laws with harsh penalties after several media reports exposed slaverylike conditions on Thai fishing vessels, Voice of America reportedLast year, the U.S. State Department downgraded Thailand to the lowest tier on its Trafficking in Persons Report 2014, which annually ranks counties on the basis of their anti-trafficking efforts.

“There continued to be reports that corrupt Thai civilian and military officials profited from the smuggling of Rohingya asylum seekers from Burma and Bangladesh (who transit through Thailand in order to reach Malaysia or Indonesia) and were complicit in their sale into forced labor on fishing vessels,” the report said.