It was the first such mass casualty in several months on a route once taken by thousands of desperate people each day.
ATHENS — The bodies of 16 people, including at least five children, were recovered from the sea off a Greek island on Saturday after a boat smuggling migrants sank in the eastern Aegean, a spokeswoman for the Greek coast guard said.
The drownings — the first such mass casualty in several months — came almost exactly two years after Turkey and the European Union signed a deal to curb the flow of migrants trying to reach Europe via the Aegean Sea.
Although the influx has been limited drastically since that time, when daily crossings were often in the thousands, hundreds continue to reach Greek islands in smuggling vessels that are often old, flimsy and unseaworthy.
The Greek authorities were alerted to the latest episode shortly after 8 a.m., when three survivors — two women and a man — swam to the island of Agathonissi and said that a boat carrying 21 people had sunk, the coast guard spokeswoman said.
“So far 10 adults are dead and five children,” she said, noting that no details were immediately available about the victims’ nationalities. “We don’t know where they came from.”
A large search-and-rescue operation was underway, involving five coast guard vessels, a boat belonging to the European Union’s border monitoring agency Frontex, a Greek air force helicopter, a Greek navy ship and four fishing boats, the spokeswoman said.
“Divers are to go out and join the search,” she added.
The reasons for the sinking were unclear: Winds on Saturday were a moderate 5 on the open-ended Beaufort scale.
“We cannot and should not tolerate losing people, losing children in the waters of the Aegean,” Greece’s migration minister, Dimitris Vitsas, said in a statement. “Clearly the solution is in finding measures to protect these people, in safe procedures and passages for refugees and migrants and in the relentless crackdown on human-trafficking rackets.”
Newly arrived migrants join thousands of others in crowded state-run camps where frustrations are growing. On Wednesday, migrants rioted at a center on the island of Lesbos, which was at the forefront of the migration crisis in late 2015 and early 2016.
At the same camp, two young Syrians and an Iraqi climbed an electricity pylon, threatening to kill themselves unless they were allowed to leave. One was hospitalized with burns after suffering an electric shock.
In a joint statement issued this month, nine rights groups — including Human Rights Watch, Amnesty International and Oxfam — denounced the island camps as “open prisons” with “deplorable” conditions, and called on the authorities to “immediately” transfer migrants to the Greek mainland.
Thousands have been moved to facilities on the Greek mainland in recent months, but the authorities have avoided transferring them all amid fears that such a move would send a message to human traffickers that the road to Europe is effectively open.
The enforcement of the migration deal signed by Brussels and Ankara two years ago is expected to be discussed at a meeting of European Union and Turkish leaders in Varna, Bulgaria, on March 26.
