The air force planes took off from Turkish bases for "an operation against two Turkish coastguard boats identified as attempting to cross into Greek territorial waters," said the private Dogan news agency.
It was not yet clear whether the vessels in the sensitive maritime region in the Aegean Sea were carrying suspected coup plotters, and a Turkish government official said he could not immediately confirm the report.
The government has cracked down hard on rebel soldiers, formally arresting 99 of 118 detained generals and admirals, and also placing in custody thousands of troops, with some later seen bruised and wounded.
The eight -- two commanders, four captains and two sergeants who have applied for asylum in Greece -- have denied any involvement and insist that they fled from Turkey to save their lives after coming under police fire.
The men, who arrived in Greece by military helicopter on Saturday after sending a distress signal to authorities at the airport in the northern city of Alexandroupolis, are to face trial for illegal entry on Thursday.