(CNN) — Malaysian authorities have uncovered 139 graves of victims caught up in the human trafficking trade in forests close to the Thai border, the country's national police chief said Monday.

Khalid Abu Bakar said that each grave, near the town of Wang Kelian, may contain the remains of more than one individual, according to Bernama, the Malaysian state news agency. He added "(Authorities) found 139 suspected graves. They are not sure how many bodies are inside each grave," he told reporters at a press conference.

The bodies are expected to be exhumed Monday. He added that police found 28 illegal camps — the largest of which may have contained up to 300 migrants.

Southeast Asia nations are facing an humanitarian crisis, as thousands of migrants from Bangladesh and Myanmar take to the sea on boats, hoping to settle elsewhere in the region.

In recent weeks, police in Thailand have reported finding graves and camps from human trafficking on their side of the border, prompting a crackdown on people smuggling from authorities there.

But that has intensified the crisis at sea. Boats carrying the migrants from Myanmar and Bangladesh have chosen to stay away from the shore, deepening the plight of the people crammed on board.

Many of the migrants caught up in the crisis are Rohingya Muslims, an ethnic minority fleeing persecution in western Myanmar. There are also Bangladeshi economic migrants seeking work in countries like Malaysia and Indonesia.

'We will find more'

Monday's grim announcement came after Malaysia said Sunday it had discovered mass graves and trafficking camps in a different area near the Thai border.

Malaysian Home Minister Ahmad Zahid Hamidi said those camps were believed to have been in operation for at least five years and were only abandoned when authorities arrived on the scene.

He said officials were still counting the number of bodies in the graves, which were found near 17 tents in the Padang Besar area of Perlis state.

"With the cooperation of Thailand, we will find more and more," Zahid told reporters.

The Prime Minister, Najib Razak, vowed late Sunday night in a tweet to bring the perpetrators to justice.

"I am deeply concerned with graves found on Malaysian soil purportedly connected to people smuggling. We will find those responsible."

Bangladeshi PM: 'Punish migrants'

According to the International Organization for Migration (IOM), an estimated 25,000 migrants took to seas in Southeast Asia in the first quarter of 2015.

In recent weeks, hundreds of migrants have come ashore in Malaysia and Aceh in Indonesia after making the risky journey south through the Andaman Sea.

Bangladesh's leader, Sheikh Hasina, said Sunday that those seeking to leave the country in an "illegal way" should be punished along with the human traffickers who facilitate their escape.

Bangladesh's leader, Sheikh Hasin

"Side by side with the middlemen, punishment will have to be given against those who are moving from the country in illegal way," Hasina told senior officials Sunday, Bangladesh's state media reported.

"They are tainting the image of the country along with pushing their life into a danger."

Authorities are standing by to repatriate 208 Bangladeshi citizens who were rescued by the Myanmar navy in its territorial waters, the state-run Global New Light of Myanmar newspaper said.

"We have been informed through sources that the rescued Bangladeshis are staying at a refugee camp located at a Madrasha building of Thandwe area of Rakhine state in Myanmar," the agency quoted Lt Col Abu Zar, a Bangladeshi border commander as saying, citing Bangladeshi media.

"Local members of United Nations High Commissioner for Refugees (UNHCR) are providing food to the Bangla language people."

The report added that there were still dozens of Bangladeshi citizens stranded at sea in Myanmar territorial waters.

U.S. military request

The Thai military said the U.S. Navy had made a request to use one of its airports to provide assistance to migrants stranded on boats in the Andaman Sea.

The U.S. had asked to keep surveillance aircraft in Phuket after the completion of anti-submarine training exercises, Thai Air Force spokesman Air Vice Marshal Montol Sanchukorn confirmed to CNN.

The U.S. and Thai armed forces took part in joint operations, codenamed Guardian Sea, last week and as a result U.S. aircraft were permitted to fly in Thai airspace.

Montol said that the U.S. request was made at an operational, rather than formal, level and was misdirected as permission to use Phuket's international airport would be granted at the discretion of Thailand's airport authority.

He said that he told U.S. military liaisons to refer their request through governmental channels.

At a meeting last week, Indonesia and Malaysia agreed to accept thousands of migrants temporarily as long as the international community helps to resettle them within one year.

Thailand has yet to announce what role it will play, although in a joint statement, the three nations said they had all taken measures beyond their international obligations — to address the "current influx of irregular migrants."

CNN's Kocha Olarn, and journalist Thasha Jayamanogaran in Kuala Lumpur, contributed to this report.

This story was first published on CNN.com, "Dozens of graves, trafficking camps found in Malaysia."