NEW DELHI: It was a mission to save their four-legged comrade that cost seven CRPF jawans their lives in a Maoist strike in Dantewada on Wednesday.An IED blast blew up their vehicle as the jawans were on their way to evacuate Scout, a Belgian Malinois who had proved his mettle as an expert sniffer dog, but was seriously ill due to dehydration in the jungle heat.Adhering to deception tactics which are part of the standard operating proce-dure, the soldiers belonging to CRPF's 230 battalion were travelling in an unmarked tempo from their post in Nerli to Bhusaras Ghati camp, about 40km away, dressed in civil clothes.They had picked up an air cooler for the dog from the Renganar camp before heading out to fetch Scout and shift him to a veterinary hospital. Along the way, at Mailavada village, the tempo was blown to pieces by Maoists , who had planted 40-50kg of explosives beneath the road.The dog, Scout, has reportedly detected a large number of IEDs for CRPF in Dantewada over the years and is considered an expert at his job. The canine had been laid low by a 'heat wave' and was seriously ill for the past several days.Initially, only four jawans were supposed to go to pick up Scout but six others from the same battalion joined them at a civil bus stop. Later, three alighted at Renganar camp. The preliminary probe suggests the Maoists dug a fox hole tunnel from near a culvert to plant the explosives beneath the blacktop road in Mailavada village.The tunnel, officials say, seems to have been dug up about 7-8 days back. The IED was exploded from a safe distance with the activation device attached to a 94-metre-long wire. The explosion left a 6.5-feet-wide crater on the road and broke the vehicle into three pieces. In a further act of brutality, officials say that three jawans, who probably were badly injured but alive after the explosion, were shot at close range in the head and chest by AK-47 rifles."CRPF takes a cautious approach while travelling in Naxal-affected areas, using civil dress and unconventional vehicles as part of the deception plan. But the deception failed this time," said an officer.He added that the Naxals probably planned the attack more than a week in advance as they wanted to strike at the time of 'Shaheed Saptah' (martyrs' week).CRPF director-general K Durga Prasad said, "Although there was no leak of information about the movement of jawans but Naxals definitely knew that the vehicle was reaching Mailavada village." Officials said that extremists either saw the jawans leaving the Renganar camp and informed the attacking party, or the jawans had stopped at a market where they were identified by Maoist sympathisers.The DG said Maoists were getting smarter at concealing deadly improvised explosive devices and were "going deeper in the countryside to plant explosives beneath normal-looking roads and travel routes".