At least 27 people, including three children, have drowned off Turkey’s Aegean coast after their boat capsized in rough seas.

Seventeen of the bodies were discovered on the shoreline in the district of Ayvalik, while ten others were found in the district of Dikili, a gendarmerie official in the local headquarters told Reuters news agency on Tuesday.

Twelve people were rescued from the sea and the rocks on the Ayvalik coastline. A coastguard official said three boats and a helicopter were searching for any survivors.

There was no immediate information on the nationalities of the dead.

Refugees are known to set off from the resort town of Ayvalik on boats to reach the Greek island of Lesbos.

On Sunday, a two-year-old boy became the first known refugee to drown in 2016 after the dinghy he was travelling in crashed on to rocks, the Greek coastguard said.

The other 39 passengers onboard were rescued after fishermen alerted the coastguard, but at least 10 were taken to hospital to be treated for hypothermia after the boat got into trouble near the island of Agathonisi.

About 850,000 migrants and refugees crossed into Greece last year, paying smuggling gangs to ferry them over from Turkey in often frail boats.

In a deal struck at the end of November, Turkey promised to help stem the flow of refugees to Europe in return for cash, visas and renewed talks on joining the EU.

Turkey is host to 2.2 million Syrians and has spent around $8.5bn on feeding and housing them since the start of the civil war nearly five years ago. Al Jazeera