PATNA: In the deadliest attack on security forces, Maoists trapped and killed 75 security personnel during Operation Green Hunt, an offensive against the Left-wing extremists, this morning in Mukrana in Dantewada district of Chattisgarh. The incident took place early morning when nearly 80 personnel from the Central Reserve Police Force and the state police were returning after opening a road for the troops, to begin an operation against Maoists. While 74 of those killed were CRPF personnel, one was a head constable of the district police. Dantewada Superintendent of Police Amresh Mishra said the Maoists first blew up a vehicle carrying the CRPF personnel near Chintalnar-Tarmetla village in the district. Immediately after the blast, the troops tried to take cover when they came under heavy fire from hundreds of Maoists. The attack shook the Centre and Prime Minister Manmohan Singh called up Home Minister P Chidambaram to make an assessment of the situation. Both of them expressed shock over the attack and grief over the loss of lives.