Violent clashes erupt in Nigeria

Troops in northern Nigeria battled gunmen who had been blamed for an attack on a police station in which 12 policemen and a civilian died.

Gunfire erupted in Kano and added to tension across the country days before a presidential vote meant to usher in the first civilian-to-civilian transfer of power in a nation whose history since independence in 1960 has been plagued by military coups.