Istanbul, Dec 23 (IANS): Four people on board were killed when an air ambulance helicopter crashed after colliding with a hospital building in Turkey's Aegean province of Mugla.

The helicopter, owned by the health ministry, lost control on Sunday due to heavy fog before colliding with the building of the state hospital, Xinhua news agency reported quoting NTV broadcaster.

Onboard the helicopter were one pilot, a technical staff member, a doctor, and a healthcare worker. Preliminary reports indicated that all four were killed, said the report.

The accident occurred during the takeoff, said Mugla Governor Idris Akbiyik.

Meanwhile, in a separate incident, eighteen people were injured in a traffic accident in western Turkey when a truck collided with a passenger bus on a highway, the state Anadolu Agency reported on Sunday.

The accident occurred on the highway near the Dinar District of Afyonkarahisar in western Turkey , injuring the bus driver and 17 passengers onboard.

The exact time of the accident is still unknown.

Health, gendarmerie and police teams were dispatched to the scene and the injured were hospitalised.