Fourteen people have been arrested in Nigeria after this week's attacks on police stations and a church in the northern city of Maiduguri.At least 14 people were killed in three explosions, including three people outside St Patrick's Catholic Church. In another incident on Tuesday, a Christian preacher was gunned down by gunmen on motorcycles.
The attacks have been blamed on the Boko Haram sect, which is fighting to overthrow Nigeria's government. Boko Haram gunmen on bikes have killed dozens of police officers and politicians during the past year.
Preacher David Usman and one of his secretaries at the Church of Christ in Nigeria were the latest victims of such shootings.
On Monday, Ibrahim Birkuti, a cleric from a different Muslim tradition who had criticised Boko Haram, was gunned down outside his home in the town of Biu, some 200 km south of Maiduguri.