The fire late on Saturday at Vial camp on Chios island destroyed the facilities of the European asylum service, a camp canteen, tents and many housing containers, Migration Ministry Secretary Manos Logothetis told AFP.
"A large part of the camp's administrative services was destroyed," said Logothetis, adding that no injuries were reported.
A local police source said three persons had been detained in relation to the unrest, which erupted after a 47-year-old asylum seeker from Iraq died in the camp on Saturday.
"We managed to restore order at around 1am... There were many people who took part in the incidents," the officer said.
The Iraqi woman had been taken with a fever to a local hospital earlier this week. At the time, a test for coronavirus had returned negative, state news agency ANA reported Saturday.
Read also: 'Catastrophe is coming': Disaster looms as coronavirus reaches Greek refugee camps
Refugee camps in Greece have been under quarantine in recent weeks, with authorities trying to keep residents apart from locals.
The virus has so far killed 110 people in Greece. Another 67 are in intensive care.
There have been coronavirus cases in two camps on the mainland.
As with all of Greece's island camps, Vial is massively overcrowded. There are more than 5,000 people living in space intended for around 1,000.
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