Myanmar immigration authorities detained 106 Rohingya Muslims aboard a boat off Yangon yesterday, officials said, raising fears of a fresh wave of dangerous voyages after a 2015 crackdown on people smugglers.

The boat was bound for Malaysia when authorities stopped it in the early morning some 30 km south of Myanmar's largest city, Kyaw Htay, an immigration officer from Kyauktan township, told Reuters by phone.

The group boarded the vessel from internal displacement camps outside Sittwe, the capital of western Rakhine state, he said.

"Their destination was Malaysia. The boat was stopped after the engine failed," he said.

Tens of thousands of Rohingya have been confined to sprawling camps outside Sittwe since violence swept Rakhine in 2012.

More than 700,000 Rohingya fled a brutal army crackdown in the northern part of the state last year, according to UN agencies. The Rohingya say soldiers and local Buddhists massacred families, burned hundreds of villages, and carried out gang rapes. U.N.-mandated investigators have accused the Myanmar army of "genocidal intent" and ethnic cleansing.

Myanmar denies almost all of the allegations, saying security forces were battling terrorists. Attacks by Rohingya insurgents calling themselves the Arakan Rohingya Salvation Army preceded the crackdown.

Officials say they are ready to accept Rohingya who want to return from Bangladeshi refugee camps. But on Thursday, efforts to repatriate several thousand failed after refugees protested, saying they did not want to return. UN officials and aid agencies opposed the plan, saying conditions in Myanmar were not safe.

Officials and aid workers told Reuters last week that dozens of Rohingya in Myanmar and Bangladesh had boarded boats to try to reach Malaysia in recent weeks after the end of the monsoon rains in early October.

Those who arrived on Friday were questioned on the top floor of a cyclone shelter, where women wearing headscarves, men, and children could be seen through the windows by Reuters reporters.

They were led to trucks as a phalanx of officials stood guard, women leading small children by the hand and some carrying small bags, before being driven away towards Yangon.

In a Facebook post, Aye Mya Mya Myo, a lower house lawmaker for Aung San Suu Kyi's ruling National League for Democracy party from Kyauktan, said there were 50 men, 31 women and 25 children in the group.

Early yesterday she posted pictures of a rickety boat crammed with people. It resembled vessels the Rohingya typically use to escape the apartheid-like conditions in Rakhine, where they are denied free movement and access to decent education and healthcare.

For years, Rohingya on both sides of the border have boarded boats organised by smugglers in the dry months between November and March, when the sea is calm. The perilous journey to Thailand and Malaysia, often undertaken in overcrowded vessels, has cost many lives.

Thailand cracked down on the trade after discovering a series of mass graves in 2015, leading to a crisis when smugglers abandoned their human cargo and left boats adrift in the Andaman Sea.