The accident occurred when passengers on board shifted abruptly to one side as a vessel from the European Union border agency Frontex approached, causing the boat to capsize.
“Their movement to the left side resulted in water entering and the boat overturning. Frontex crew immediately launched life cushions and a lifeboat,” the Greek coast guard said in a statement.
Fifty-five people were rescued, including one injured individual who was taken to a hospital on nearby Crete. Survivors indicated that more passengers were on the boat when it went down, a coast guard officer said. Four vessels and a Frontex aircraft are involved in ongoing search efforts.
Greece, which faced a migration crisis in 2015-16 when over a million people arrived from the Middle East and Africa, has seen a recent spike in migrant boats arriving at Crete and Gavdos, mainly from Libya. Deadly incidents remain frequent.
Last week, at least 42 migrants were reported missing and presumed dead after a rubber boat capsized off the Libyan coast, according to the International Organization for Migration.
In response to increasing migratory pressures, the European Commission announced that Greece, Cyprus, Spain, and Italy will be eligible for support under a new EU mechanism once the bloc’s migration and asylum pact comes into effect next year.