Lusaka, Oct 16 (IANS) At least four people were killed and 29 others seriously injured following a road accident in Kafue District, about 40 km south of Lusaka, the capital of Zambia.Rae Hamoonga, spokesperson for the Zambia Police Service, said that the accident occurred in the early hours of Tuesday on a major highway when a public bus carrying an undisclosed number of passengers overturned."Preliminary investigations indicate that the accident occurred due to excessive speed, which caused the driver to lose control of the vehicle," he said in a statement, Xinhua news agency reported.The police spokesperson added that the dead included a male adult, two female adults, and a female minor.On Monday, five people died in Zambia's Chisamba District when a vehicle they were travelling in collided with an oncoming truck.Fatal road accidents, which are common in Zambia, are mainly caused by careless driving, poor road conditions, and overloading.--IANSint/jk/kvd