At least 58 people died and many were missing after a boat carrying illegal migrants sank off Turkey's western Aegean coast on Thursday morning, Turkish media reported.

Speaking live on state television TRT, Tahsin Kurtbeyoglu, the governor of Menderes, a coastal district in Izmir province, confirmed the sinking.

TRT reported that the boat had sunk around dawn after travelling just 50 meters from the Turkish coast. Television footage showed small boats searching for survivors close to the shore.

State-run Anatolia news agency, citing Kurtbeyoglu, said on its website that most of those on the boat were Palestinian nationals and that the destination of the boat was not known.

So far 46 people have been rescued alive, Anatolia reported, including the boat's captain and his assistant who have both been arrested. Those rescued were in good health, it said.

Turkey's location as a bridge from Asia to Europe, as well as its wealth compared with neighboring states, has long made it both a destination and a transit point for migrants from as far afield as sub-Saharan Africa and South Asia.