At least three people were hurt in a clash between asylum-seekers in a town on the Greek island of Samos, police sources said Tuesday.
They said the violence, apparently between groups of Syrians and Afghans, erupted in the town of Vathy late on Monday.
A fire later broke out outside the camp that authorities managed to place under control early on Tuesday morning.
"Half of the 6,000 people who are stuck in Vathy camp on Samos are women and children," medical charity MSF said in a tweet.
"This nightmare must end! Children and other vulnerable people must be evacuated from the Greek islands to safe accommodation."