Large plumes of smoke could be seen billowing from Moria refugee camp in Lesbos, as seen on drone footage from Thursday.
The fire comes just a day after a massive blaze swept through the camp, causing destruction of large parts of the camp.
After the major blaze on Wednesday, some locals reportedly attacked migrants and prevented them from passing through a village situated close by while they were evacuating from the flames.
The camp was placed under quarantine last week after the first COVID-19 case appeared at the overcrowded camp. A 40-year-old Somalian man tested positive after having returned to the island after not being able to settle on the Greek mainland and was put in isolation to curb the outbreak.