At least 10 migrants including five children died early Dec. 23 when their boat sank near the Greek Aegean island of Farmakonissi, the national ANA news agency said.
Another 13 people were rescued and two more are feared missing in the latest Aegean Sea tragedy, the agency said.
The accident coincided with an announcement by the UN refugee agency and the International Organization for Migration (IOM) that more than one million migrants and refugees reached Europe this year.
The vast majority of people -- over 800,000 -- landed in Greece, according to the figures.
On Dec. 22, 12 migrants including four children drowned off the coast of Turkey when their boat sank.
Some 700 people, many of them children, have lost their lives trying to cross the Aegean to Greece this year, according to the IOM, many of them refugees fleeing conflicts in Syria and elsewhere.
Nearly 3,000 others have died on the perilous Mediterranean crossing to Italy.