QUITO, Sept. 16 (Xinhua) -- At least five people were killed and 27 others injured when a bus overturned in Ecuador's central province of Chimborazo on Sunday, the ECU 911 emergency services reported.

An emergency call at 3:46 a.m. local time (0846 GMT Sunday) alerted authorities to the roadway accident and five ambulances were dispatched to the crash site at the entrance to the town of Columbe.

The bus was reportedly carrying sightseers from the southern city of Cuenca towards the nation's capital Quito.

"The injured are receiving medical treatment at the site of the accident and being transported to the hospitals in (the towns of) Colta and Riobamba (Chimborazo's capital )," said the services.

Two Fire Department rescue units and four national police patrol cars were also dispatched, but the rescuers were able to get to the bodies only after removing the vehicle.

The cause of the accident has yet to be determined, but officials suspect the vehicle hit a barrier before turning over.