ATHENS, Nov. 1 (Xinhua) - A rescue operation was underway on Tuesday off the coast of Evia island in the Aegean Sea, after a boat carrying a yet unclear number of migrants sank, Greek national news agency AMNA reported.

Nine people have been rescued so far who told local authorities that a total of 68 persons were on board when the incident occurred.

The operation was hampered by strong winds of up to 9 on the Beaufort scale blowing in the area, AMNA added.

More than one million people have illegally entered Greece since 2015 and most have continued their journey to other European countries, while hundreds have drowned at sea, according to Greek official data.