MAIDUGURI, Nigeria, Oct. 23 (UPI) -- A suicide bombing Friday during morning prayers at a Maiduguri, Nigeria, mosque killed at least 18 people and critically injured 20 more.
Emergency officials said the explosions were timed so the second bomb could injure those who offered aid to the victims of the first.
Last Friday in Maiduguri, birthplace of the Boko Haram radical Islamist group and capital of Nigeria's northeastern Borno state, another explosion in a mosque killed 37 people. Four suicide bombers killed four people in the city suburbs.
No group has claimed responsibility for Friday's incident, but the methodology of the attack was consistent with Boko Haram's approach. The group has made clear it intends to build a fundamentalist Islamic state with Maiduguri as its capital.
Advocacy group Amnesty International said earlier this month that Boko Haram has killed at least 16,000 civilians in Nigeria since June, and more than 3,500 this year.