Eighteen people were killed after the bus they were travelling in collided with a truck in Nigeria's Ogun state, authorities said on Saturday.The accident occurred on Friday.The passengers, who were students of the Olabisi Onabanjo University in Ago-Iwoye area of the state, died on the spot, Xinhua news agency reported. The Commander of the state-owned Traffic Compliance and Enforcement Corps in Ijebu-Ode told Xinhua that the truck driver was driving against traffic and collided with the commercial bus, killing all the occupants, including the bus driver."I was coming from Sagamu when I saw the accident. I hurriedly park my car and ran there to see if the passengers could be rescued. But unfortunately all the occupants, including the driver died," he said.