Four migrant children drowned on Tuesday while trying to cross from Turkey to Greece after a boat carrying about 27 people sank, the Greek migration minister said.
Greece is one of the main routes into the European Union for asylum-seekers crossing from Turkey in flimsy, overcrowded rubber boats but the number of people arriving has fallen sharply in recent years and deadly shipwrecks in its waters have become rare.
The shipwreck occurred off the Greek island of Chios.
Migration Minister Notis Mitarachi said the four children were aged between three and 14. Twenty-two others were rescued and one person is believed to be missing, he said. Their nationalities were not immediately made public.
"This is the reality of the exploitation of migrants by criminal gangs in the Aegean," Mitarachi tweeted.
"Unscrupulous smugglers endangering lives in overcrowded, non-seaworthy boats off Chios," he added, posting a picture of an inflatable dinghy at sea, apparently the one involved in Tuesday's incident.
Ten vessels and two helicopters had assisted in the rescue operation, the coast guard said.
Nearly 1 million people, mainly Syrian refugees, arrived in the EU in 2015 after crossing to Greek islands close to Turkey.
About 6,500 asylum-seekers have arrived in Greece this year, mostly through its northern eastern land border with Turkey, according to data by the United Nations refugee agency UNHCR.
