The United Nations refugee agency said it was concerned by reports that Bangladeshi police had arrested Rohingya refugees fleeing a controversial island camp and that others were hurt in a protest about conditions there.
Bangladesh has shifted 18,000 refugees out of a planned 100,000 to the low-lying silt island of Bhashan Char from squalid, cramped settlements on the mainland where 850,000 of them live.
With some of the Rohingya saying they were coerced into being relocated and that conditions on the island are poor, in recent weeks 59 of them were arrested after escaping.
The UNHCR said in a statement on Wednesday after a four-day visit to Bangladesh that it "remains concerned about reports of refugees being arrested and detained for attempting to leave Bhashan Char".
While the UNHCR inspected the island on Monday, several thousand Rohingya held a protest against conditions there, with some throwing rocks and smashing windows, police said.
The UNHCR said it was "deeply concerned to learn of reports of refugees who were injured" during the demonstrations.
It added that those on the island, which critics say is vulnerable to the cyclones that hit the region, needed "access to meaningful livelihoods opportunities, skills development, education, health and access to cash to facilitate their daily lives".
It added that it "strongly discourages the use of relocation (from the mainland camps) to Bhashan Char as a punitive measure", something which Bangladesh denies doing.
Two Rohingya refugees who fled the island recently told AFP hundreds of refugees have escaped but island police chief Mahe Alam put the number at fewer than 100.
"Bhashan Char has some potential, though the human and protection elements of refugees living there must be fully considered," said UNHCR Assistant High Commissioner for Protection Gillian Triggs.
"They should have freedom of movement on the island and must be granted the possibility to return to Cox's Bazar (on the mainland) and to maintain family connections with those in the camps," said Triggs.
Most of the 850,000 Rohingya in Bangladesh had fled a brutal military offensive in neighbouring Myanmar in 2017 that UN investigators concluded was executed with "genocidal intent".
Praising Bangladesh for its "humanitarian spirit", the UNHCR said the recent military coup in Myanmar makes "prospects of voluntary repatriation in the short term more challenging".
It also lauded efforts to stop the spread of coronavirus in the camps but "observed a reduced humanitarian presence in the camps and associated protection risks".