Addis Ababa, Sep 20 : A traffic accident in Ethiopia's Oromia regional state has left six people dead, local officials said. The traffic accident happened in Adaba district, located in the West Arsi zone of the Oromia region, on Monday when a midibus traveling on the road plunged into a gorge, leaving six people dead, state-affiliated Fana Broadcasting Corporate (FBC) quoted local officials as saying. Police further said some 15 others sustained serious and light physical injuries from the accident. The injured are currently receiving medical treatment in nearby healthcare institutions, Xinhua news agency reported. Police attributed the main cause of the incident to overload, in which the midibus with a capacity of transporting 28 people was carrying 40 people during the time of the accident. Although Ethiopia has one of the lowest per capita car ownership rates in the world, deadly traffic accidents are fairly common, with the blame often put on bad roads, reckless driving, a flawed driving license issuance system, and lax enforcement of safety rules. /IANS