The group was found off the town of Methoni on the Peloponnese peninsula, stranded on a chain of rocky islets. They have since been taken to Methoni to be processed and identified, according to harbour police.
Authorities will be eager to determine the group’s route, which deviated from Aegean Sea route typically followed by migrants crossing from Turkey to Greece.
Between Thursday and Friday morning, 261 new arrivals were registered on the Aegean islands — mainly Lesbos — an increase on recent days, according to the SOMP agency which is coordinating Greece’s response to the migrant crisis.
The number of new arrivals is however considerably lower than the peak of last summer when an average of 100 migrants were arriving daily.
The influx has declined dramatically following a controversial EU-Turkey deal in March.
Under the deal, Turkey agreed to take back Syrians who make it to Greece, in return for being allowed to send one from its massive refugee camps to the EU in a more orderly redistribution programme.
Last week there were between 13 and 147 new arrivals every day.
Both Greece and the EU fear that the migrant floodgates could re-open as Turkey focuses on a purge of officials following the failed coup of July 15 which has led to a souring of relations between Ankara and Brussels.
Some 10,000 migrants remain encamped on the Aegean islands — which have a capacity to host just 7,450 migrants — with most claiming asylum to either avoid or postpone their forcible return to Turkey under the deal.