RAIPUR: Maoist unleashed a major attack on Central Reserve Police Force ( CRPF ) team in tribal Bastar district of Chhattisgarh, killing three people and critically injuring nearly 20 others on Tuesday morning.Police said a team of 80th battalion of CRPF was part of a road opening party (ROP), which had left Tongpal on patrolling, when the rebels triggered a powerful Improvised Explosive Device (IED) and later opened indiscriminate fire. Indications are that causalities could go up further and details will be known only when rescue and relief team reached the spot in Sukma district.The incident took place near Tongpal, an area close to Jheeram Gathi were senior Congress leaders were killed in Maoist ambush on May 25 last year.A police spokesman told TOI that a helicopter has been pressed into service to evacuate the injured from the spot while senior police officials, along with additional reinforcement of security forces have been rushed to the spot.“ The exact number of causalities are immediately not known. The injured are now being shifted to vehicles”, a police official in Bastar said.