Greece recovered the bodies of four dead migrants and rescued 27 after their boat sank off the island of Kos in the southeastern Aegean Sea, the Greek coastguard said late on Tuesday.
Three coastguard ships and a commercial vessel were searching for more people in the area, it added.
In a separate incident early on Wednesday, a cargo ship rescued 96 migrants after their boat sank off the tiny island of Gavdos, near the island of Crete in the Mediterranean Sea, the coastguard said.
It said one of its vessels with four other ships and a helicopter were searching for any missing people amid moderate winds.
Greece was at the frontline of a migrant crisis in 2015-2016 when more than a million people, mostly Syrian refugees, crossed from Turkey to the country by sea, mostly on inflatable dinghies.
The number of arrivals fell before resurging last year as many migrants attempted the new southern route through Gavdos.
