100 people were killed in bomb attacks and gunbattles in the Nigerian city Kano late on Friday, a local government security source said, in the deadliest strike claimed by Islamist sect Boko Haram to date. "Definitely more than 100 have been killed," the senior source, who could not be named, told Reuters. "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 on Saturday for the wave of strikes. The sect has killed hundreds in the north of Africa's most populous nation in the last year. The attacks late on Friday prompted the government to announce a dusk-to-dawn curfew in the city of more than 10 million people, the country's second biggest. President Goodluck Jonathan, who has been criticized for failing to act quickly and decisively enough against Boko Haram, said the killers would face "the full wrath of the law." 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.