Thousands of people fled from a fire at a migrant camp on Lesbos on Monday night, a police official on the Greek island said, noting that there had been tension among residents earlier in the day.
The fire brigade was investigating the cause of the fire, the official said.
"There is a big fire at the hot spot (migrant camp). Almost all the migrants evacuated," said the official, who declined to be named. "There was tension in the evening. Our main concern is the safety of the people. The fire is quite big."
Greece is struggling to reduce overcrowding at migrant camps on its islands, even though the flow of people is less than last year, and the slow processing of asylum requests is adding to frustrations that sometimes spark violence among residents.
More than 13,500 migrants and refugees are now living on five Greek islands close to Turkey, with capacity for 7450, according to government data.
Including those on the islands, there are 60,000 migrants stranded in Greece, most of whom have made risky journeys across the Mediterranean Sea to escape war and poverty in Africa and the Middle East.
About 5650 migrants and refugees are being housed on Lesbos in facilities equipped for 3500 people.
