The death toll from coordinated bombings in the northern Nigerian city of Kano climbed to at least 24 on Saturday, witnesses said, dpa reported.
Officials earlier confirmed that at least 10 people were killed.
Witnesses told dpa that they counted bodies, which numbered at least 24, from the Friday afternoon attacks.
Paramedics said the death toll could rise. Many of those wounded suffered severe burns in the bombings that targeted police stations in several parts of the city.
Among those killed was television reporter Eneche Akogwu, 31, who was shot dead while interviewing witnesses.
An overnight curfew was imposed in Kano, after the four blasts. But gunshots were heard early Saturday.
Witnesses said they saw teenagers throw explosives into the grounds of the Immigration and Passport Office. A suicide bomber reportedly drove a car packed with explosives into the city's police headquarters.
Witness Jafaru Isaw said he saw "mangled bodies being removed from the debris," followed by "intermittent gunshots."
"It looked like one of those incredulous things you see in a war movie, the shootings were deafening," he said.
The radical Islamist group Boko Haram claimed responsibility for the attacks. In a statement, the group said the blasts were revenge for the recent arrests of Boko Haram members in Kano.
"We are compelled to write this letter to inform Kano residents of this development," wrote the group's leader, Abubakar Shekau.
Boko Haram is calling for Sharia law to be implemented across Nigeria, and for recognition of growing tensions between the country's predominately Christian south and Muslim north.
Police stations are an obvious target for the group.
President Goodluck Jonathan has boosted the numbers of the emergency taskforce, and police raids on the homes and factories of suspected Boko Haram militants have increased.
The country's police chief, Hafiz Ringim, called for an investigation into Friday's blasts, which he described as "well-coordinated attacks."
But Ringim is under investigation himself, after a suspect charged with carrying out Christmas Day bombings on churches, escaped from police custody earlier this week.
Some Nigerians have called for Ringim's resignation. Many Nigerians are angry that the president has not yet addressed the nation in the wake of the latest bombings.