Four Rohingya refugees were killed during a gunfight between two insurgent groups in Bangladesh, police said Wednesday, in the latest sign of deteriorating security in the country's overcrowded relief camps.

Bangladesh is home to around a million members of the stateless and mainly Muslim minority, most of whom fled a 2017 military crackdown in Myanmar that is now subject to a United Nations genocide probe.

The dozens of squalid refugee camps housing the Rohingya have emerged as a battleground between rival armed groups who have used the settlements as staging posts for drug trafficking and human smuggling.

Local police chief Shamim Hossain told AFP that an hourlong shootout took place between the Arakan Rohingya Salvation Army and Rohingya Solidarity Organization on Tuesday night.

"Four Rohingya refugees were killed and two Rohingya were seriously injured," he added.

Neither group gave immediate comment on the clash.

The RSO has been challenging the larger and more established ARSA for control of the camps since the start of the year, coinciding with a crackdown on ARSA by Bangladeshi security forces.

Violence has long been a fact of life for those living in the refugee settlements.

Police say more than 60 Rohingya refugees have been killed in Bangladeshi camp clashes this year, including women and children.

The United Nations Refugee Agency said Sunday it was "alarmed by the continuing deterioration of security conditions in the camps."

Malnutrition is also widespread, with the UN food agency saying a funding shortfall this year had forced it to cut rations by a third.

Those Rohingya remaining in Myanmar face severe persecution by authorities who deny them citizenship and access to healthcare.

The desperate situation both there and in the Bangladeshi camps has prompted thousands of Rohingya to embark upon dangerous and often deadly sea trips to Southeast Asian countries to escape.