European border officials are being pulled out of Greek islands over concerns for their safety, following a spate of riots and violence by migrants.

Since March, migrants arriving on the Greek islands have been prevented from moving on to the mainland as the European Union (EU) hopes to return at least some of them to Turkey.

But due to growing frustrated at the delay, the migrants have taken to burning down their accommodation and rioting, the Daily Mail has reported.

As a result, Belgium has taken the decision to withdraw its staff from the islands, fearing for their safety.

Belgium’s migration secretary Theo Francken told Belgian newspaper De Standaard, “The security situation has worsened. The atmosphere is particularly grim because asylum seekers, often single men, are stuck there and realise they cannot journey on to Germany or Belgium.

“Some express their frustrations in a particularly aggressive fashion. In recent days asylum agency staff have been targeted.

“We would like to show our solidarity with the people of Greece, but the safety of our staff is our priority.

“The Greek authorities must take action. I warned them several months ago. They have done too little.”

Last week 37 migrants were detained by the Greek police on Chios after a crowd of over 100 migrant men blocked a road, throwing fireworks and rocks at officers. The following night a makeshift camp for migrants was targeted and burned to the ground.

“Both incidents together have destroyed the places to sleep for some 100 men women and children. Today there was a third incident where …. stones were thrown and one Syrian man was seriously injured to his head and had to be hospitalised,” said Roland Schoenbauer, spokesman for UNHCR Greece.

Order was restored after riot police were dispatched. It was the third such incident in the last month. Similar incidents have occurred on nearby Lesbos, where in September the island’s largest camp was burned down, leaving thousands homeless.

The office of the European Asylum Agency, located on Lesbos, was also torched.

More than 51,000 migrants are currently stranded in Greece according to figures from the UN’s refugee agency, of which around 16,000 are stuck on the islands.

Lesbos is currently hosting 6,142 migrants even though its capacity is 3,500. Similarly, Chios currently has 4,143 migrants despite having just 1,100 places for them.