Suspected Boko Haram gunmen shot dead nearly 80 people in separate attacks on three villages at in Nigeria's restive northeast Borno state on the weekend, a vigilante and residents said yesterday. Vigilante Babakura Kolo said 68 people were killed in the attack on Banu village late Friday while residents said another 11 people were shot dead in two other villages in the state on Saturday and Sunday. Meanwhile, Nigeria's security agency said it had made significant breakthroughs in the fight against Boko Haram and arrested 20 prominent members of the group accused of orchestrating deadly attacks.