Twenty-eight migrants died when a wooden smuggler's boat capsized in the Aegean Sea. A coastguard spokesperson said half of those who had died were children, including four infants.
Around 98 passengers were rescued from the boat, with more able to swim to the Greek island of Farmakonisi in the south-eastern Aegean Sea. The victims' nationalities have not been determined. The death toll is expected to rise further.
According to Greek authorities, the Greek Ministry of Shipping's Unified Coordination Centre for Search and Rescue received a call about several migrants being in danger in the region. A Super Puma helicopter set off for the port of Mytilene in search of the boat.
The latest drowning tragedy came as Germany's interior minister warned migrants will not get to choose what country they go to under a proposed European Union quota system to share the burden of new arrivals. Interior Minister Thomas de Maiziere told the Tagesspiegel daily that if refugees get protection in Europe they must accept being distributed around the EU.
"There can be no free choice of residence for refugees," he said. "That doesn't exist anywhere in the world."
Meanwhile, a rally and march in solidarity with migrants in Athens, was attended by around 500 people. Those at Saturday night's rally carried banners declaring "Refugees Welcome" and "Deportation for Racists". The protesters peacefully marched a block to the European Union offices before dispersing, according to Associated Press.
More than 300,000 migrants have crossed into Greece so far this year straining the country's inadequate resources and causing resentment among inhabitants of Greek islands close to Turkey, where the migrants come ashore, according to AP.
Polls show the far-right, anti-migrant Golden Dawn party is in third place, a week ahead of a snap national election. There are concerns the migrant issue could lift its support past the 10% mark.