The deaths provoked a protest among other asylum seekers who have been stuck at camps described as open-prisons. The police clashes injured six asylum seekers, according to Greek media.

The latest violence and death follows similar incidents in other camps on the Greek islands with reports emerging of suicides, gang rape, sexual abuse of small children, and fights.

Fires had already ripped through Moria camp, home to around 4,000 migrants, in late September. Mounting frustrations over the slow pace of registration, along with rumours of mass returns to Turkey, reportedly factored into the blaze.

Last week, assailants had also tossed petrol bombs and large stones at tents at the Souda camp in Chios. The attackers are thought to be linked to the Golden Dawn, a Greek neo-nazi party. The unrest appears to have been triggered, in part, after four Algerian teenagers and one Iranian allegedly stole fireworks from a local shop.

The Belgium government, meanwhile, repatriated experts working on the islands due to the widespread insecurity. Belgium's far-right asylum minister Theo Francken, in an interview with a Belgian newspaper last week, announced he had ordered their return.

The EU commission has in the past said it cannot be held responsible for the deteriorating security among the overcrowded camps because they are managed by the Greek government.

'They are going to get angry'

"A large number of people on the islands are not processed and is creating and fueling tensions on a daily basis," said Vincent Cochetel, the director of the Europe branch of the UN’s refugee agency, at an event in Brussels in September.

"You have on a daily basis people who commit suicide, burning things, Afghans, Iraqis, Palestinians are not processed on the islands," he said.

Some have not have their application claims fully registered since the launch of the hotspots earlier this year.

"If you keep people in that sort of condition they are going to get angry," he said.