Four female teenage suicide bombers killed two people and injured 16 others in a residential area in the northeast Nigerian city of Maiduguri, a disaster agency spokesman said on Wednesday, APA reports quoting Reuters.
The girls knocked on the door of a house and then detonated their devices, a representative of the state-run emergency service in Borno State said.
The focus on individual homes is a new tactic.
"Community leaders should create awareness among residents not to open their doors for anybody (if) they are not aware of the visit," Borno police commissioner Damian Chukwu said.
The blasts in the Muna Garage area, on the edge of the city worst hit by jihadist group Boko Haram's eight-year insurgency, occurred around 1:15 a.m (0015 GMT), National Emergency Management Agency (NEMA) spokesman Abdulkadir Ibrahim said.