At least eight people - including a child - have drowned after a speedboat carrying migrants capsized in the Aegean Sea during a chase with a Greek patrol vessel.
The coastguard said the boat's driver "lost control" in the attempt to escape from the patrol ship.
The boat was travelling at high speed and collided with the side of a Greek coastguard vessel as it was trying to get away, according to local media reports.
So far 18 people have been rescued from the sea, the coastguard said, with many of the survivors suffering from injuries after the incident.
Friday's incident happened near the island of Rhodes, close to the Turkish coast, on a route that is often used by migrant smugglers.
A helicopter and coastguard ships are continuing the search for any further survivors.
Greece's shipping minister Christos Stylianides expressed his "deepest sorrow" for the loss of lives, saying his goal was to tackle the "ruthless" people smugglers who sacrifice lives for profit.
Thousands of migrants trying to reach Europe by boat die in the Mediterranean every year.
Last month eight people, including six children, were recovered after a migrant boat sank off the Greek island of Samos.
So far this year, more than 50,000 migrants have arrived in Greece by boat, making it the second most used European migrant route behind only Italy.
Migrant arrivals had been steadily declining since August 2023, but increased again since the summer, according to data from United Nations refugee agency, UNHCR.
About 180,000 migrants have arrived in Europe by sea this year, agency figures show, while 2,000 people were dead or missing. Around 23% of arrivals were children.