At least five people, including a child were killed when a boat sank off the Greek island of Samos in the Aegean Sea, Greek sources said Saturday.
Around 11 people were on the boat at the time the incident took place, sources said, adding that five of them were rescued.
Rescue teams were now looking for the remaining missing person, they added.
Over the past year, thousands of people have made short but perilous journeys across the Aegean in a bid to reach northern and western Europe.
The EU-Turkey agreement allows for the return of “irregular migrants” to Turkey from Greece in exchange for Syrian refugees to be relocated within the EU. The first batch of returnees arrived in Dikili on April 4.
The deal also provides a six billion euro ($6.8 billion) aid package to help Turkey care for millions of refugees, visa-free travel for Turkish nationals within the EU and fast-tracked EU accession for Turkey.
It is aimed at breaking the people smuggling gangs who have been trafficking refugees across the Aegean Sea, resulting in hundreds of deaths, according to EU and Turkish officials.
According to the International Organization for Migration, more than 152,000 people have crossed the Aegean Sea from Turkey to Greece so far this year and 366 have died during the voyage.