DHAKA: Hundreds of Rohingya rescued by Bangladesh and sent to a flood-prone island after being stranded at sea for weeks should be moved to existing refugee camps, the UN secretary general said.

The appeal by Antonio Guterres to Bangladesh's foreign minister in a letter comes as concern grows over a coronavirus outbreak in the sprawling, crowded camps near the border with Myanmar.

The Rohingya were rescued in early May after floating adrift in the Bay of Bengal. Dhaka has said they were sent on to the camps in the southeast as authorities were afraid they might have Covid-19.

Guterres said the 308 refugees on Bhashan Char island — a silty strip of land prone to violent and potentially deadly monsoon storms should be moved to the camps after their time in quarantine is completed.

Nearly 1 million Rohingya live in squalid camps in Cox's Bazar. Many fled Myanmar after a 2017 military crackdown. Emergency teams are racing to contain the spread of the coronavirus in the camps after three Rohingya tested positive late last week.