KANO, Nigeria: An explosion rocked an area near a mosque in the violence-torn city Nigerian city of Maiduguri on Friday, residents said, but it was unclear whether there were any casualties.

The blast comes after a series of Christmas attacks in Nigeria blamed on Islamist sect Boko Haram killed at least 42 people, most of them outside a Catholic church near the capital, and set off fears of reprisals from Christians.

"There was a loud blast near the mosque just after the Friday prayers as people were trooping out of the mosque," one resident said. "Everybody scampered to safety, leading to a stampede."

Boko Haram has carried out scores of attacks in Nigeria, most of them in the northeast. The group's targets in that region have included Muslim leaders.

Thousands have fled Maiduguri fearing further attacks by Boko Haram and heavy-handed military raids, with soldiers accused of killing civilians and burning their homes after bomb blasts.