Greece's coast guard says it has rescued hundreds of migrants in more than a dozen search and rescue operations, including one in which a toddler was found unconscious in one of the overcrowded dinghies.

The coast guard said Wednesday it had picked up 534 migrants in 14 incidents off the coasts of the eastern Aegean islands of Lesbos, Chios, Agathonissi, Samos, Farmakonissi and Kos from Tuesday morning to Wednesday morning.

Separately, it said a child of about 2 or 3 years old was found unconscious in a dinghy spotted by a patrol helicopter and carrying 54 migrants off Samos. A coast guard vessel picked up the group and the child was transported to a hospital.

Greece has been overwhelmed with record numbers of migrant arrivals this year, most from Syria.