A suicide bomber detonated explosives in Nigeria on Sunday, killing four people and injuring 35 others, a Nigerian media outlet reported. According to AP, there was no immediate claim of responsibility for the attack in Potiskum in northeastern Nigeria. Extremists from the Boko Haram group have recently escalated attacks and seized more territory in the northeast of the West African nation. The attack happened at around 10 a.m. near a gasoline station in Potiskum, the largest commercial center in Nigeria's Yobe state, Channels Television said. It cited a witness as saying the injured were rushed to a nearby hospital for treatment.