Greece recovered the bodies of four dead migrants and rescued 27 others 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.
President Donald Trump said the US was considering "winding down" its military operation against Iran, as Iran and Israel traded attacks on Saturday and Iranian media said the nuclear enrichment facility in Natanz had been attacked.
Robert Mueller, the no-nonsense former FBI chief who documented Russia's interference in the 2016 US election and its contacts with Donald Trump's campaign but opted not to bring criminal charges against a sitting president, has died at age 81.
Fourteen people died and 25 were seriously injured in a fire at a car parts factory in the South Korean city of Daejeon, fire authorities said on Saturday.
Russian attacks on Ukraine killed two people in Zaporizhzhia and left most of the northern region of Chernihiv without power on Saturday, Ukrainian officials said.