Kano - Loud explosions and gunfire on Monday evening rocked Nigeria's restive northern city of Maiduguri where unknown gunmen earlier in the day shot dead a traffic warden, residents and journalists said.
More than a dozen loud explosions were heard in the Gomari-Costain district of the city. Gomari primary school as well as a telecommunications mast near it were ablaze, the sources said.
There were no immediate reports of casualties or who was behind the explosions and gunfire which created panic in the city.
Authorities deployed troops and armoured tanks on the streets of the city after the attacks as residents, traders and motorists swiftly left the streets deserted and locked themselves in their homes.
Earlier in the day, gunmen fired killed a traffic warden, residents said.
The military Joint Task Force did not respond to telephone calls on the situation in the city.
Maiduguri, capital of north-eastern Borno state, was on Sunday rocked by a roadside blast and two separate gun attacks that killed at least four people including a local chief, according to residents and the military.
The city is a stronghold of Islamist group Boko Haram but it was not immediately clear who was behind the latest violence.
Boko Haram has repeatedly attacked Christians attending Sunday worship across northern Nigeria.
The sect has said it wants to create an Islamic state in the mainly Muslim north of Nigeria, Africa's most populous country, where most people in the south are Christian.
The group is blamed for killing more than 1 400 people in Nigeria since 2010.