Nigerian police have shot dead four members of the Islamist sect Boko Haram in the northeastern city of Maiduguri.
Bomb attacks and fierce gun battles between the sect and police in Nigeria's second largest city Kano on Friday killed at least 178 people, according to hospital staff.
Kano is hundreds of kilometres west of Maiduguri, Boko Haram's home town.
"Four members of Boko Haram sect involved in killings in Maiduguri and environs have been under surveillance of security agencies and have been shot dead in Pomomari area of Maiduguri yesterday," an officer in the joint military task force said in a statement.
"Various IED (improvised explosive device) materials prepared for detonation were recovered from their car."
Boko Haram, which was formed in Maiduguri in 2002, has killed hundreds of people in the last year, mostly in and around its home state of Borno, though its attacks have been spreading across the north of Africa's most populous nation.
Residents in Kano, a city of more than 10 million people, began to return to work today amid a heavy military presence as soldiers searched vehicles at dozens of checkpoints set up on the city's streets.
President Goodluck Jonathan has been severely criticised for not getting a grip on Boko Haram, a group he says have infiltrated the police, military and all areas of government.
Boko Haram, a Hausa term meaning "Western education is sinful", is loosely modelled on Afghanistan's Taliban.
The sect originally said it wanted sharia, Islamic law, to be applied more widely across Nigeria but its aims appear to have changed.
The sect focuses its attacks mostly on the police, military and government, but has attacked Christians more recently.
It says it is fighting enemies who have wronged its members through violence, arrests or economic neglect and corruption.
