At first, the Islamic extremists in Nigeria's dusty northeast rode on the backs of motorcycles, firing on government officials and other targets with worn Kalashnikov assault rifles hidden beneath their flowing robes. Now, they come prepared for war.

Islamic fighters invaded a town in northeast Nigeria on Tuesday and used anti-aircraft guns, mounted on the back of trucks, to destroy nearly every landmark of the nation's federal government. In other assaults the insurgents fired rocket-propelled grenades.

The militarization of Islamic radicals, and the willingness of extremists to use their new weapons, highlight the increasing instability in Nigeria's north and the ever-growing dangers facing the nation's weak central government.