ANKARA (Reuters) – A plastic boat carrying 22 migrants sank off Turkey’s Aegean coastal town of Kusadasi on Friday, killing 11 people and leaving four missing, the Dogan news agency (DHA) said.

Television footage showed bodies washed up on a beach near the town. Rescuers managed to save seven people from the stricken vessel and the coast guard was searching for any other survivors, Dogan said.

A deal between Turkey and the European Union on curbing illegal migration, struck a year ago, helped reduce the migrant influx to Europe via Greek islands to a trickle. But some are still trying to make the perilous voyage across the Aegean.

Just 3,629 refugees and migrants have crossed to Greece from Turkey so far this year, according to the United Nations refugee agency UNHCR, and about 60 arrive on Greek islands each day. At least 173,000 people, mostly Syrians, arrived in 2016.

Europe’s deteriorating relations with Turkey could endanger the deal, under which Ankara helps control migration in return for the promise of accelerated EU membership talks and aid.

President Tayyip Erdogan said on Thursday that Turkey would review all political and administrative ties with the EU after an April referendum, including the migrant deal.

Erdogan has been angered by Germany and the Netherlands cancelling planned rallies on their territory by Turkish officials seeking to drum up support for a “yes” vote in the referendum, which could lead to constitutional changes extending the powers of the presidency.

(Reporting by Tuvan Gumrukcu in Ankara and Karolina Tagaris in Athens; Writing by Nick Tattersall)