The dead were four children, four women and one man.
It was not immediately clear how the boat overturned, or what the passengers` nationality was.
Europe faces a massive refugee crisis. More than 600,000 people have made their way through Greece so far this year, fleeing war and poverty at home. The vast majority do not stay in the country, heading north through the Balkans to more prosperous European Union countries.
More than 500 people have died or are missing since the beginning of the year.
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