A coordinated attack in Nigeria's second largest city by the radical Islamist sect known as Boko Haram has shown its metamorphosis from a group that had lone motorcycle-riding gunmen to a fearsome band of killers moving with military precision.
Police say at least 185 people were killed in Friday's attack in Kano, a city of more than 9 million people.
The assault bore the hallmarks of long-term planning. Cars were loaded down with explosives and were driven by those willing to die. Others wore security uniforms and shot any official who believed they belonged to the government they despise.
Analysts say Nigeria's ill-equipped police and military are overstretched and unable to confront the new threat threatening peace in Africa's most populous nation.