Five people died after a boat carrying illegal migrants capsized off Turkey's northwestern coast on Sunday, state media reported.

The Turkish coastguard found the bodies after the rubber vessel sank off the Enez district in Edirne province, Anadolu news agency said.

Fearing the numbers on board could be higher, the coastguard continued search and rescue efforts, the agency added.

The cause of the incident was not yet known but a Mediterranean storm is battering Greece and brought heavy rain and wind to Turkey's Aegean cities.

The agency did not give details of the migrants' nationalities however Turkey hosts over three million Syrian refugees and up to 300,000 Iraqis.

It is also one of the transit countries used by those fleeing war and poverty to try and reach Europe.

The flow of refugees into Europe has slowed since the influx hit a peak in 2015 when over a million people landed in Greece from Turkey, the majority via boats.