At least 36 migrants, including children and a pregnant woman, drowned in the Aegean Sea off Turkey after two rubber boats capsized, the Anadolu news agency reported Tuesday citing the Turkish coast guard.
The migrants were attempting to reach the Greek islands in stormy weather. Bodies were washing up in the areas of Ayvalik and Dikili, CNN Turk said.
The coast guard rescued 12 people, Anadolu reported, and the refugees were believed to be from Iraq, Syria and Algeria.
Many of the victims had poor-quality life jackets that are being sold illegally to the migrants on the Turkish coast.
Police Tuesday seized more than 1,000 such inferior vests from an illegal production shop in Izmir, Turkey. Two Syrian children also worked in this facility, CNN Turk reported.
Last year, the Aegean became a main gateway for migrants, mainly refugees from Syria and other conflict zones in the Middle East and Asia who hope to find shelter in wealthy European countries.
About 850,000 people crossed the waterway to Europe in 2015, according to UN data. The surge continues despite the massive risks of crossing in rickety and unstable vessels and harsh winter weather.
According to the latest figures from the International Organization for Migration, at least 3,771 people drowned in the Mediterranean last year, with more than 800 in the Aegean.
Turkish authorities say they are sheltering 2.2 million refugees from Syria alone in 25 camps.
Turkey agreed in talks with the European Union in November to improve control over its borders and slow the flow of migrants, but without a significant result so far.
The Greek coast guard said two ferries brought 2,477 migrants from Lesbos and Chios to Athens early Tuesday, while 1,880 people arrived the previous evening.
From Greece, the refugees continue their travel towards western and northern Europe.
Since the second half of November, countries further along the Balkan route - Macedonia, Serbia, Croatia, Slovenia and Austria - have stopped all so-called economic migrants and are allowing only Syrians, Afghans and Iraqis to pass.
Hungary, which sealed its border to all migrants in September, on Monday sent 31 police officers to Macedonia to help the country filter refugees from economic migrants on the border with Greece.
Slovak Prime Minister Robert Fico and Interior Minister Robert Kalinak on Tuesday said their country will send a contingent of 25 policemen to Macedonia.
Hungary and Slovakia legally challenged the EU refugee redistribution plan at the European Court of Justice.
The EU decided on September 22 to distribute 120,000 refugees from Italian and Greek refugee centres across the 28 member states in line with mandatory quotas. Slovakia, Hungary, the Czech Republic and Romania voted against.