Members of the extremist group, Boko Haram, have launched a fresh offensive on Maiduguri, the capital of Borno State, reports say.
The militants are pushing to enter the town, sources said.
Residents who were obviously caught unawares are said to be scrambling home to safety.
The Hausa service of the BBC reports that troops from the Nigerian army are presently engaging the attackers.
The reports say the attackers came through an area called “Cashew Plantain” which is behind Gina Barracks, the headquarters of the 7th Division of Nigerian army.