Greek coast guard officers move a baby from a dinghy carrying refugees to a coast guard vessel, during a rescue operation in the open sea between the Turkish coast and the Greek island of Lesbos.

Twenty-seven migrants, 11 of them children, drowned off Turkey's Aegean coast as they tried to reach a Greek island, the Turkish coast guard said yesterday.

Four migrants were rescued and a search operation was under way for nine remaining passengers.

One migrant was rescued by a fisherman and three more were rescued by the coast guard, which said it had deployed boats and helicopters to search for more passengers.

The boat sank in the Aegean Sea near the Edremit area of the northwestern province Balikesir.

Separately, the private news agency Dogan said 11 migrants died and three were rescued when another boat sank further south, off the coast of Dikili in the province of Izmir.

More than 900,000 people fleeing Syria, Afghanistan and other war-torn or impoverished countries arrived in Greece from Turkey last year, often risking their lives in the short but perilous sea crossing in overloaded boats. Hundreds have died making the attempt.

Turkey, which is hosting at least 2.5 million refugees from Syria's civil war, has become the main launchpad for migrants fleeing conflict, persecution and poverty to Europe.

The deaths came as German Chancellor Angela Merkel was meeting Turkish officials in Ankara for talks on reducing the influx of migrants to Europe.

The Turkish government struck a deal with the EU in November to halt the outflow of refugees, in return for €3bn in financial assistance.

Last week the EU finally reached an agreement on how to finance the deal.

But the deal and the onset of winter do not appear to have deterred the migrants, with boats still arriving on the Greek islands daily.

Earlier, dozens of Greek riot police were deployed to a demonstration organised by the extreme right Golden Dawn party against plans to build a new transit camp for refugees and migrants near Athens.

Four of the party's 18 policymakers were at the rally outside the port of Perama where the government is planning to build the camp.

Greece is under pressure from the European Union to complete screening centres on five islands and increase its capacity to house asylum-seekers and detain migrants facing deportation.

Defence minister Panos Kammenos said the centres would be completed within a week.

The International Organisation for Migration (IOM) said the number of refugees and migrants who perished in the Mediterranean in January alone topped 360.

Turkey has come under mounting pressure to open its border to assist the fleeing Syrians, many of whom have been sleeping in cold weather in open fields near the Bab al-Salameh border crossing.

The Turkish deputy premier said Ankara had reached the end of its "capacity to absorb" refugees. The governor of the border province of Kilis said Turkey would provide aid to the displaced within Syria, but would open the gates only in the event of an "extraordinary crisis".

Gains by the Syrian army have allowed troops to almost fully encircle Aleppo, Syria's largest city and one-time commercial centre, preparing the way for a blockade.

The main supply line to the Turkish border has already been cut and many residents of the city are looking to leave, anticipating severe shortages in coming days.

The army has been aided by massive Russian airpower and dozens of fighters from the Lebanese Shiite Hezbollah group as well as Iranian fighters.

The capture of Kfeen took troops to about 5km from the town of Tel Rifaat, and 30km from the Turkish border - the closest reached by government forces since they lost Mannagh air base in mid- 2013.

In January, almost 62,200 migrants and refugees entered Europe through Greece, according to the IOM, most of them from Syria, Afghanistan and Iraq.

Smuggling

Turkey agreed in November to fight smuggling networks and help curb irregular migration. In return, the EU pledged the money to help improve the condition of refugees, and to grant political concessions to Turkey, including an easing of visa restrictions and the fast-tracking of its EU membership process.

Turkey has since started to require Syrians arriving from third countries to apply for visas, in a bid to exclude those who aim to continue on to Greece.

Turkey has also agreed to grant work permits to Syrians as an incentive for them to stay in Turkey, and has announced plans to increase coast guards' capabilities and designate human smuggling as a form of organised crime - which would bring stiffer punishments.

Irish Independent