ATHENS (AFP) - Migrants at a camp on the Greek island of Lesbos hurled stones at the police and torched seven temporary offices used by asylum officials in an hour-long protest on Monday (Oct 24) over conditions, officials said.

Mr Jose Carreira, executive director of the European Asylum Support Office (EASO), said at least four containers where interviews were conducted were entirely destroyed, and three more were damaged.

"Incidents have occurred in the past but this is the most serious one... We are looking into ways of guaranteeing that this might not happen again," said Mr Carreira, who is in Athens for meetings with Greece's Immigration Ministry.

EASO staff left the scene, Mr Carreira said, and no one was hurt in the incident as the blaze was quickly brought under control by firefighters.

However, it could take days before asylum interviews can resume, he added.

Around 70 migrants took part in the protest, most of them from Pakistan and Bangladesh, a local police source said. Police made a dozen arrests.

The incident took place at the Moria camp, one of five centres on Greek Aegean islands, which have borne the brunt of Europe's migrant crisis.

More than 15,000 migrants are being held on the Aegean islands, pending their return to Turkey under an EU-Turkish agreement reached in March this year.

Processing has been held up because the vast majority have filed for political asylum.

Moria has a capacity for 3,500 people but currently houses more than 5,000.

Part of the camp was badly damaged in a fire on September 19 during clashes between migrants and police, and thousands had to be moved out before returning two days later.

Nearly 66,000 refugees and migrants are currently stranded in Greece, according to official figures.