At least eight people have died after boats carrying over 100 displaced Rohingya capsized off western Burma’s coast on Monday night, as they attempted to flee ahead of a tropical cyclone heading towards the conflict-torn region, the UN has confirmed.

Forty-two people have been found alive, according to the UN Office for the Coordination of Humanitarian Affairs (UNOCHA), while over 50 others are still missing near Pauktaw in Burma’s Arakan state.

“Last night there was a boat in the area of Pauktaw that left one of the IDP camps to go to a safer location and that was with the blessing of the authorities,” UNOCHA spokesperson Barbara Manzi told DVB from the Arakan state capital Sittwe on Tuesday morning. “Unfortunately as they moved they hit a rock and they capsized.”

The displaced Rohingya are believed to have fled ahead of Cyclone Mahasen, a tropical storm, which is expected to hit southern Bangladesh by Thursday morning, causing life-threatening winds, rains and floods across large parts of northern Arakan state, where nearly 70,000 stateless Rohingya Muslims are stuck in low-lying camps near the sea.

The missing Rohingya are understood to have escaped in a convoy of boats, led by a larger engine-driven boat dragging four smaller non-motorised vessels. All five boats reportedly sunk when the largest one struck rocks.

Manzi said that it was likely to have been a “spontaneous” rather than an “organised” movement, possibly fuelled by growing distrust between the Muslim Rohingya and state officials. But it does not appear to have been prevented by the authorities, who have previously been implicated in mass atrocities against the stateless minority in westernBurma’s Arakan state.

Activists have already expressed concerns that state officials could use Cyclone Mahasen as an opportunity to further persecute the Muslim minority, who are denied citizenship and basic rights by the Burmese government.

“If the government fails to evacuate those at risk, any disaster that results will not be natural, but man-made,” Brad Adams, Asia director at Human Rights Watch, warned on Tuesday.

Pauktaw township, which hosts over 17,000 displaced Rohingya some 27 km (17 miles) east of Sittwe, has been identified as one of the areas most vulnerable to flooding when Cyclone Mahasen hits. On Monday, aid workers told DVB that authorities had failed to implement an effective evacuation strategy for the region.

Some 140,000 people, mostly Muslim Rohingya, were displaced in two bouts of ethno-religious clashes with Buddhist Arakanese in western Burma last year, and have been confined to squalid makeshift camps since then.