Greece has said it has prevented about 600 migrants from crossing the Aegean into its territorial waters from neighbouring Turkey, according to the state broadcaster and other media.
A spokesman for the Greek coastguard on Monday told the AFP news agency that five sail boats and four dinghies had set off from the Turkish coast early in the morning.
Speaking to Greek radio, a coastguard officer estimated the total number of migrants on board the sail boats alone at 450.
“Greek patrol vessels were able to quickly locate the vessels and inform the Turkish coastguard,” the spokesman told AFP.
All the vessels either headed back or were intercepted, he added.
“All the incidents occurred inside Turkish territorial waters” between the Greek islands of Chios and Samos, he said.
According to Greek coastguard sources, about 22,000 migrants have been prevented from entering the European Union along this route since the start of the year.
Athens regularly blames Ankara for not taking sufficient action to curb people smugglers who send out migrants in unsafe boats and dinghies from its shores, in breach of a 2016 accord with the EU.
Greece is a member of the 27-nation bloc but Turkey is not.
Greece’s tough border controls have been dogged by accusations from rights groups that the Greek coastguard has been engaging in illegally forcing migrants to return to Turkey.
Athens has always denied that its security forces engage in illegal pushbacks.
In March, Greece’s national transparency authority said a four-month investigation found no evidence of such practices.
EU border agency Frontex has also repeatedly been accused by rights groups of illegally returning migrants across EU borders.
Frontex head Fabrice Leggeri resigned last month amid an investigation by the European anti-fraud office OLAF, reportedly into alleged mismanagement.