Abuja: Seven persons, including six civilians and a customs officer have been killed by members of Nigeria's radical Muslim sect Boko Haram in northern city of Maiduguri.

The gunmen stormed Silimanti, Polo area of the town, at around 8.30 am on Thursday and fired gun shots at men working at a bakery, killing at least five people there, sources said.

They also killed a water hawker and the customs officer at a separate location during their escape.

Spokesman of the Police in Borno State Samuel Tizhe confirmed the killings, insisting that "investigations have since then commenced into the incident."

"I can confirm that a Customs officer and a water hawker were shot dead, while five people were shot dead by suspected Boko Haram members at a bakery," Tizhe said.

Boko Haram claims to be waging war to install an Islamic government and Sharia rule in Africa's largest oil producing nation.

The group's insurgency has been growing in Nigeria and an attack in the northern city of Kano with multiple bombings and gun shots killed around 185 persons on January 20.