ATHENS — At least 46 people, including 17 children, drowned Friday in the Aegean Sea as two smuggling boats sunk off different Greek islands. A search-and-rescue operation was underway for others feared trapped in the wreckage.

Greek coast guard ships and other vessels saved more than 70 people from the sunken boats.

The new drownings follow hundreds over the past year as Europe faces its worst immigration crisis since the end of World War II. More than a million people seeking asylum have entered the continent in 2015 — most through Greece, coming across the sea in small smugglers’ boats from Turkey.

The European Union is deeply divided on addressing the influx, with several countries blocking or restricting migrants from entering and resisting plans to share the refugees. In the meantime, Germany — where most immigrants are heading — has welcomed those it considers refugees.

EU foreign policy chief Federica Mogherini said Friday the 28-nation bloc faces big economic risks if its member countries start putting up walls between each other, because of the refugee crisis, that restrict borderless travel. Austria this week set a cap on the numbers of refugees it will take.

In the first sinking Friday in the eastern Aegean Sea, a wooden boat carrying 49 people foundered off the Greek islet of Farmakonissi. Forty people made it ashore, while authorities rescued one girl and recovered eight bodies.

A few hours later, a wooden sailboat carrying an undetermined number of people sank off the islet of Kalolimnos, south of Farmakonissi. The coast guard rescued 22 men and four women, and recovered 35 bodies.

The Turkish coast guard said it rescued six survivors from the area of the two accidents and found another three bodies.