A boat believed to be carrying around 300 migrants from Myanmar capsized in the Indian Ocean last week near the maritime border between Thailand and Malaysia, leaving at least one person dead, 10 rescued, and many still missing, officials said Sunday.

Authorities said the exact location and time of the sinking remain unclear.

Malaysian officials suspect the vessel overturned in Thai waters, noting that human smuggling syndicates are increasingly using dangerous sea routes to traffic migrants across borders. Police confirmed that several of the rescued passengers are Rohingya Muslims, a persecuted minority group from Myanmar.

First Admiral Romli Mustafa of the Malaysian Maritime Enforcement Agency (MMEA) said preliminary findings suggest the boat departed from Buthidaung, a town in Myanmar’s Rakhine State, and went down three days ago.

Search and rescue operations began Saturday after several survivors were spotted drifting near Malaysia’s northern resort island of Langkawi. The body of a woman, believed to be from Myanmar, was also recovered from the sea, he said.

“So far, 10 people have been rescued, including a Bangladeshi man and several Myanmar nationals,” Romli said, adding that more victims may still be found as the operation continues.

Kedah State Police Chief Adzli Abu Shah told Malaysia’s national news agency Bernama that the vessel likely sank in Thai waters before survivors drifted toward Malaysian territory.

Earlier this year, in January, Malaysian authorities turned back two boats carrying nearly 300 suspected Rohingya refugees attempting to enter the country illegally. Malaysia, a Muslim-majority nation, has long been a preferred destination for Rohingya fleeing persecution in Myanmar.

Although Malaysia has previously accepted Rohingya on humanitarian grounds, the government has sought to restrict new arrivals amid fears of mass migration by sea.

According to the U.N. High Commissioner for Refugees (UNHCR), about 117,670 registered Rohingya currently live in Malaysia, accounting for nearly 59 percent of the country’s total refugee population.