Kano, Nigeria (CNN) -- Nearly a week after a spate of bombings and shootings in northern Nigeria killed more than 200 people, authorities are fighting to stay ahead of the militants blamed for the attacks.
Hundreds of improvised explosive devices in soft drink cans have been found across the city of Kano, where the violence raged Friday, police said Thursday.
An IED in a soft drink can exploded Thursday morning at a bus park in the city, Nigeria's second largest, where hundreds of passengers had been waiting to catch buses out of town, police said.
The makeshift device caused no casualties, but it led to the discovery of an explosives-packed gallon drum hidden among other fuel drums at the park, police said.
Police officers and plainclothes security officers refused the CNN crew entry to the transport park, as the deactivation was in progress. They shouted away bystanders and threatened motorists who were slowing down to take a look at the scene.
A sense of fear was pervasive across Kano on Thursday. As military helicopters flew low overhead, both civilians and government officials shied away from the CNN camera, telling the crew they were frightened of being targeted by Boko Haram.
The Islamist militant group has been blamed for months of widespread bloodshed in Nigeria. It claimed responsibility for Friday's attacks in a phone call to the Daily Trust, according to journalists at the newspaper.
A joint military force arrested 158 suspected members of the group this week, security sources said.
Boko Haram has been implicated in the assassination of critics, including five men killed in front of their families in the northeastern city of Maiduguri this month.