The north of Nigeria has been hit by a series of bomb attacks.<br /><br />In one of them at least four children were killed when a device exploded near a church, <br /><br />That blast came just hours after a suicide bomber targeted a police station in the capital, Abuja, killing two people.<br /><br />Authorities say an Islamist sect known as Boko Haram is responsible for the attacks.<br /><br />Al Jazeera's Yvonne Ndege reports from Abuja.
