The truck was loaded with iron ore and 27 members of a marriage party were seated atop the ore heap when the vehicle ran into a tractor coming from the opposite direction on the bridge at Garka village, last evening.
The truck driver lost control and it went off the bridge, said district police officials.
Seven of the marriage party died on the spot, while three others died in hospital. Nine of the injured were being treated at a hospital in Keshkal, officials added.
The truck was proceeding from Jagdalpur to Raipur.
Chief Minister Raman Singh today declared an ex-gratia grant of Rs one lakh each for the families of the deceased and Rs 25,000 to each of the injured.