The north of Nigeria has been hit by a series of bomb attacks.

In one of them at least four children were killed when a device exploded near a church,

That blast came just hours after a suicide bomber targeted a police station in the capital, Abuja, killing two people.

Authorities say an Islamist sect known as Boko Haram is responsible for the attacks.

Al Jazeera's Yvonne Ndege reports from Abuja.