Ten people, including children, have died after four boats sank off Greek islands in the eastern Aegean Sea.
Hours earlier the Greek coastguard had rescued 242 people from a sinking boat in the area.
Thousands have been arriving on the island of Lesbos every day after making the dangerous journey from Turkey.
Meanwhile, many are still using the perilous route from the Libyan coast - Italian authorities say 1,042 people were rescued in the area on Wednesday.
Seven separate rescue operations were carried out on Wednesday morning, Italian media reports say.