KANO, NIGERIA — Nigerian security forces killed a man and his pregnant wife early Tuesday in an assault on a neighborhood in this northern city, where an attack four days ago by a radical Islamist sect killed at least 185 people, witnesses said.
Meanwhile, police Tuesday showed journalists explosives used by the sect known as Boko Haram during its attack Friday in the sprawling city of Kano and acknowledged some gunmen wore uniforms resembling those of paramilitary police and soldiers.
Police said they found 10 unexploded car bombs and hundreds of small homemade bombs after Friday's attack.
Witnesses said security forces surrounded a home early Tuesday in Nigeria's second-largest city and started a gunbattle that lasted hours.
The man who was killed was a retired worker from the country's Education Ministry and had no involvement in Boko Haram, said Musa Ibrahim Fatega, a relative of the slain man.
Assault-rifle rounds left bullet holes in the cement walls of the home attacked by security forces. Its interior metal doors were peppered with holes. Inside a living room, blood pooled around beige sofas, with a single rifle cartridge left behind. A man in traditional robes sobbed as he stood in the puddle.
A sedan inside the compound, also riddled with bullet holes, bore federal government license plates.
Security forces took away the two bodies, with family members still trying to figure out how to reclaim them for burial before sundown according to Islamic tradition.
"He didn't belong to any religious group. Is it because of his beard?" Mr. Fatega asked. "That means you cannot dress the way you are. Is it good? Is this how government is going to treat us?"
The scene around the house was tense as onlookers pressed against the front gate. A military attack helicopter circled overhead.
Kano state Police Commissioner Ibrahim Idris told journalists Tuesday afternoon that a "sister agency" had carried out the attack on the house.
Typically, police use that term when referring to the State Security Service, the country's secret police.
Marilyn Ogar, a secret-police spokeswoman, could not be reached for comment.
Friday's assault killed at least 150 civilians, 29 police officers, three secret police officers, two immigration officers and one customs official, police said, bringing the death toll to 185 dead.
Medical workers and emergency officials said they expect the toll to rise even further.
The coordinated attack was Boko Haram's deadliest since it began a campaign of terror last year. Boko Haram has killed 262 people in 2012, more than half of the 510 people the sect killed in all of 2011, according to an Associated Press count.