The incident took place late evening at Kokanara village, nearly 375 km from Raipur, Inspector General of Police (Bastar Range)
T J Longkumer said.
Ten personnel were injured in the blast. They are being taken to a hospital in Jagdalpur.
The CRPF personnel were returning from patrol duty to Tonagapal from Sukama and had taken lift in the truck when they were ambushed, police said, adding that Maoists and security personnel also exchanged fire.
