The blast occurred in a thickly forested stretch of Tongapal area in Dantewada district, some 500 km south of here, when a search squad of the Central Reserve Police Force (CRPF) and District Force (DF) was on its way back to the base camp.
Maoists also fired at the ambushed patrol, but the troopers instantly retaliated, killing seven rebels.
"Despite being hit by a massive blast, the jawans showed bravery and a fair amount of courage and retaliated against the Maoists, who were in dozens and armed with sophisticated weapons," T J Longkumer, Inspector General of Police Bastar, said.
He said the bodies of seven insurgents were recovered.
About a dozen CRPF troopers sustained multiple injuries and were admitted to Maharani Hospital at Jagdalpur, headquarters of Bastar district.
The blast, the latest in a string of Maoist attacks on policemen in iron-ore rich and tribal dominated Bastar, has shaken up the state police authorities as they are clueless how to handle the leftist insurgents.
A police officer based at Sukma, the town nearest the attack site, said that it was a meticulously planned attack as the rebels on Saturday morning set a few trucks of a private contractor on fire in Tongapal, in order to lure the security personnel to the site.
The officer claimed the CRPF men who visited Tongapal disregarded security advice and took a lift in a private truck on their way back to camp.
Deccan Herald is on WhatsApp Channels| Join now for Breaking News & Editor's Picks