At least 15 migrants have died after a speedboat carrying them collided with a Hellenic Coast Guard vessel off the coast of the island of Chios late on Tuesday.

Greek authorities said the speedboat was making dangerous manoeuvres and that a pursuit was under way at the time of the collision in the Chios Strait, near the village of Vrontados.

Twenty-four people were rescued, some of whom were seriously injured, and others are reportedly still missing.

The coastguard has not yet clarified the exact circumstances around the collision.

A search and rescue operation was ongoing on Tuesday night, which involved four coastguard vessels, a privately owned boat carrying civilian divers, and a helicopter.

Greek state broadcaster ERT said the injured included seven children, a pregnant woman and two coastguard officers. (BBC)