Mass graves and suspected human-trafficking detention camps have been discovered by Malaysian police in towns and villages bordering Thailand, the country's home minister said on Sunday.
Home Minister Ahmad Zahid Hamidi said officials are determining whether the graves were of human-trafficking victims, but did not say how many dead bodies were discovered.
"This is still under investigation," he told reporters on the sidelines of an event in Kuala Lumpur.
According to media reports, the mass graves were believed to contain the bodies of hundreds of migrants from Myanmar and Bangladesh.
Police discovered 30 large graves containing the remains of hundreds of people in two places in the northern state of Perlis, which borders Thailand, the Utusan Malaysia newspaper reported.
The Star newspaper reported on its website that nearly 100 bodies were found in one grave on Friday.
"I reckon it was a preliminary finding and eventually I think the number would be more than that," Ahmad Zahid said when asked about reports on the number of mass graves discovered.
Ahmad Zahid said the camps identified are in the areas of Klian Intan and villages near the border.
"They have been there for quite some time. I suspect the camps have been operating for at least five years," he said.
A police spokeswoman declined to comment, saying a news conference on the issue would be held on Monday.
A police official who declined to be identified said police commandos and forensic experts from the capital were at the site but it was unclear how many graves and bodies had been found.
"Of course I believe that there are Malaysians involved," Ahmad Zahid said, when asked about possible involvement of locals in the incident.
Northern Malaysia is on a route for smugglers bringing people to Southeast Asia by boat from Myanmar, most of them Rohingyas, who say they are fleeing persecution, and people from Bangladesh seeking work.
Smugglers have also used southern Thailand, and police believe the discovery had a connection to mass graves found on the Thai side of the border this month.
Twenty-six bodies were exhumed from a grave in Thailand's Songkhla province, over the border from Perlis, near a camp with suspected links to human trafficking.
Since May 10, more than 3,600 people — about half of them from Bangladesh and half Rohingya from Myanmar — have landed ashore in Indonesia, Malaysia and Thailand.
Thousands more are believed to be trapped at sea in boats abandoned by their captains.
On Saturday in Vietnam's capital, Hanoi, U.N. Secretary-General Ban Ki-moon said he has been speaking to regional leaders about the crisis and urging them to find a solution.
Malaysia and Indonesia announced last week that they would provide temporary shelter for up to one year for migrants recently found or still stranded at sea. The U.S. has said it will settle some of them permanently.
Four Malaysian navy ships began searching for migrant boats Friday, but their operation is limited to Malaysia's territorial waters. The Pentagon said Thursday that Washington was readying air patrols to aid in the search, but a U.S. Embassy spokeswoman in Bangkok said the offer of assistance was still awaiting clearance.
The Rohingya, numbering around 1.3 million in Myanmar, have been called one of the most persecuted minorities in the world. Long denied basic rights, they have been driven from their homes in mob attacks in Myanmar's Rakhine state several times since 2012.
More than 140,000 Rohingya were displaced and are now living under apartheid-like conditions in crowded camps. More than 100,000 more have fled by sea.