More than 100 people have been killed in bomb attacks and gunfights in Nigeria's second largest city Kano, a senior local government security source told Reuters, in the deadliest coordinated strike claimed by Islamist sect Boko Haram to date.
"Definitely more than 100 have been killed," the source, who could not be named, said. "There were bombs and then gunmen were attacking police and police came back with attacks." Hospital staff said there were still bodies arriving at morgues in Kano.
Boko Haram claimed responsibility for the attack on Saturday. The sect has killed hundreds in the north of Africa's most populous nation in the last year.
The attacks late on Friday (local time) prompted the government to announce a dusk-to-dawn curfew in the city of more than 10 million people.
Kano and other northern cities have been plagued by an insurgency led by Boko Haram, which is blamed for scores of bombings and shootings. These have taken place mostly in the Muslim-dominated north of Africa's top oil producer, whose main oil-producing facilities are located to the south.
Aimed mainly at government targets, the Boko Haram attacks have been growing in scale and sophistication.
A spokesman for Boko Haram contacted reporters in the northeastern city of Maiduguri, where the sect is based, to claim responsibility for Friday's bombings. Copies of a letter apparently from the group were also dropped around Kano.
The letter, written in the Hausa language spoken in northern Nigeria, said the attacks were retribution for police arrests and killings of members of the sect.
Police said in a statement they were doing their best to bring the situation under control. "(We are) appealing to members of the public to come forward with information on the identity and location of these hoodlums."
The police said eight buildings were attacked, including police headquarters, three police stations, the headquarters of the secret services and the immigration head office. Shooting between police and gunmen went on into the night, residents said.
"We are still going around collecting corpses," a spokesman for the National Emergency Management Agency in Kano told Reuters. "They are mostly police officers ... some died from injuries from explosions, some from gunshot wounds."
Witnesses said smoke billowed from the police headquarters after the blast blew out the windows, wrecked the roof and triggered a blaze that firefighters struggled to control.
In one shooting late on Friday, unidentified gunmen killed a cameraman for Nigeria's Channels TV, Akogwu Enenche, who had recently also contributed stories to Reuters Television, while he was filming at the scene of one of the bombings, witnesses and his family said.
The police did not comment. Enenche was on a Channels TV assignment when he was shot.
"We are shocked and saddened at the death of Channels TV reporter Akogwu Enenche who has contributed footage to Reuters over the last few months. Our thoughts go out to his friends and family at this very sad time," Thomson Reuters Editor-in-Chief Stephen Adler said in a statement.
Boko Haram became active around 2003 in the northeast state of Borno but its attacks have spread into other northern states, including Yobe, Kano, Bauchi and Gombe.
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. Recent messages from its leaders have said it is attacking anyone who opposes it, at present mainly police, government and Christian groups.
"My brother was killed last night in the gunbattle with Boko Haram at the state police headquarters, he had only two years left in the service, he was an Assistant Superintendent," said one police officer, who asked not be named.
"Many families are still looking for members as everybody was running for safety from the gunbattles."
The African Union on Saturday condemned what it said were the latest "terrorist" attacks in Kano.
A bomb attack on a Catholic church just outside the capital Abuja on Christmas Day, claimed by Boko Haram, killed 37 people and wounded 57.
The main suspect in that attack, Kabiru Sokoto, escaped from police custody within 24 hours of his arrest, and police have offered a 50 million naira ($US309,600) reward for information leading to his recapture.
Police arrested him on Tuesday and he escaped when their vehicle came under fire as they were taking him from police headquarters to his house in Abaji, just outside Abuja, to conduct a search.
Last August, a suicide bomber blew up the U.N. Nigeria headquarters in Abuja, killing at least 24 people.
There were two blasts in the southern state of Bayelsa in the oil-producing Niger Delta late on Friday but no one was killed. Police said they were not linked to Boko Haram.
Bayelsa, the home state of President Goodluck Jonathan, is holding a governorship election next month. Troops have been deployed in the state in recent weeks to stem political unrest.
