Police said they have found 28 human-trafficking camps near its northern border with Thailand and 139 suspected graves containing an unknown number of bodies.
Police Inspector-General Khalid Abu Bakar said Monday that the nationalities of the deceased were unknown, though local media say the graves include bodies of Rohingya Muslims from Myanmar. Khalid said exhumation work would begin immediately and forensic teams would work to identify the corpses found in the northern state of Perlis.
Tens of thousands of Rohingya have fled in recent years from majority-Buddhist Myanmar, where they are denied citizenship and have endured attacks on their homes and businesses. Their end destination is often Malaysia, though many transit through Thailand and fall victim to human traffickers who hold them for ransom in jungle camps.
Mass graves were uncovered at abandoned camps on the Thai side of the border earlier this month, prompting a crackdown on smuggling. That has left hundreds, perhaps thousands, of asylum seekers stranded at sea, risking a regional humanitarian crisis as governments debate how to address the issue.