Four children are missing after a dinghy carrying migrants capsized off the Greek island of Samos, the Athens News Agency reported on Saturday.
The coastguard located and rescued 24 people from the vessel in the eastern Aegean Sea early on Saturday.
But they said five people were missing, four of them children, and a rescue operations are under way, the agency reported.
This new incident comes more than a week after international public opinion was appalled by the bleak image of a Syrian toddler, Aylan, lying face down on a Turkish beach.
The toddler drowned along with his mother and brother when their boat capsized on a short run from Turkey to the Greek island of Kos in hope of a new life in Europe.
The International Organisation for Migration said over 430,000 migrants and refugees crossed the Mediterranean to Europe so far in 2015, with 2,748 dying or going missing en route.
Greece's minister in charge of shipping, Christos Zois, said on Friday that the situation in Lesbos, a Greek island struggling with a huge influx of migrants, "is getting normalised".
He added that 22,500 migrants and refugees were taken to Athens this week.