Four CRPF jawans were today shot dead and another injured in sleep by their "mentally disturbed" colleague in the Naxal-hit Dantewada district of Chhattisgarh, police said.        

"The shooting occurred last night at the camp of 111 CRPF Battalion in Aranpur area of the Naxal-dominated district, when the constable Deep Kumar Tiwari opened fire on the jawans who were sleeping," Dantewada SP Narendra Khare told reporters.        

Inspector General, CRPF, Zulfiqar Hasan said a court of inquiry has been initiated into the case. While three jawans died on the spot, one succumbed while being taken to hospital, Khare said, adding that the injured trooper has been air-lifted to Raipur and admitted to MMI hospital in Raipur.        

The exact cause of the shooting was being ascertained even as the preliminary investigation indicated that the accused constable had been going through some "mental problems", the SP said.        

Those killed have been identified as -- head constable Chandan Singh (45) from Gujarat, constable Ramesh Kumar (29) from Haryana, constable Aniruddh Kumar (24) from UP and constable Purushottam Lal Sahu (29) from Raipur.