The partially sunken boat was found on Saturday by a Turkish merchant ship. Two survivors were rescued. A multi-ship and aircraft operation was launched to search for more victims.
Greece is a common route into the EU for people fleeing conflict and poverty in Africa, the Middle East and Asia.
In recent months, crossings from Libya to Crete have increased, while the dangerous route from Turkey to the Greek islands has become less common. It is unclear where the boat in question came from.
