Five people were killed and another severely wounded when a boat carrying migrants hit a Turkish coast guard vessel off northwest Turkey, a local governor's office said, adding a search operation was underway for a missing person.

In a statement, the governor's office said a high-speed boat carrying 34 migrants and one migrant trafficker hit the coast guard vessel off Ayvalik district's Badavut coast.

"As a result of the search and rescue operations in the region, it was determined that five people who fell into the sea lost their lives."

"One person, a woman, was severely wounded and sent to hospital," it said, adding authorities were still searching for one missing person.

An investigation has been launched into the incident by the Ayvalik prosecutor's office, it said.

The Aegean Sea is a frequent transit route for migrants attempting to cross from North Africa and the Middle East into Europe.