Two boats carrying migrants to Greece capsized near Turkey on Monday, killing at least 33 refugees.
Quoting Turkish media, the Anadolu and Dogan agencies, BBC reported that 22 people died close to the Greek island of Lesbos.
Dogan said another 11 people died in a separate incident further south, near Dikili in Turkey’s Izmir province.
CNN reported, Three helicopters and patrol boats from the Greek coastguard and the European border agency Frontex were part of the rescue operations, alongside fishing vessels.
About 850,000 refugees crossed into Greece last year, paying smuggling gangs to ferry them over from Turkey in often frail boats.
On Friday, German Chancellor Merkel said that unilateral measures by European Union member states would not solve the refugee crisis, which requires a joint effort.
Up to 5 February, at least 374 people had died crossing into Europe this year, the International Organization for Migration (IOM) says.
The sea route from Turkey to Greece was the most popular way for migrants to try to enter Europe in 2015.
In October, four boats carrying refugees from Turkey to Greece sank in the past few hours, leaving at least 11 people dead and more than 40 others missing, Greek authorities said on Thursday.
On 31 January, more than 40 people including women and children had drowned in the Aegean Sea after their boat capsized
This also included least 10 babies and young children.
The vessel was en route to the Greek island of Lesbos when it sank near the resort of Ayvacik.