agartala: four cops were shot dead in an exchange of fire between tripura and meghalaya police personnel at dharmanagar in north tripura district on friday morning. two were seriously injured. the broad daylight shootout between the police forces lasted about 90 minutes. the incident was a fallout of mistaken identity when both force were chasing a gang of kidnappers. among the killed are a deputy superintendent of police and a meghalaya police inspector. the meghalaya police, led by inspector pratap chhetri, was chasing a gang of suspected militants who had reportedly kidnapped a girl, nayank aggarwal, from a shillong school on march 14. the kidnappers had called up the aggarwal family on march 21 and told them the ransom money was to be paid in dharmanagar to a man with a ‘red cap’ who would arrive in the town on friday morning in a private bus. the meghalaya police informed the tripura police. dsp (intelligence) kalyan sarkar with 15 personnel , all in civil dress and heavily armed, laid an ambush in the bus complex waiting for the ‘red cap’. the five meghalaya police personnel, also in civvies, were also keeping a watch for ‘red cap’. a bus arrived at dharmanagar at 9.40 am and a man with ‘red cap’ got off. he was apparently waiting for the man who would bring the ransom money. “when kalyan sarkar saw the man with the red cap board an auto rickshaw, he took out his firearms. constable nanigopal debnath followed. at that moment the meghalaya police mistook sarkar and the constable for the other members of the kidnappers’ gang and opened fire. both died on the spot,� said a senior police officer here.