Locals in Nigeria's northeastern city of Maiduguri have been without power for a week after jihadists blew up supply lines from the national electricity grid.

It has caused water shortages disruptions to daily life and businesses.

"The lack of light is seriously affecting our business. Our business is not going smoothly like before. People are coming to buy some things but now the business is not going, the business is so bad," said Jefari Mamuda, an appliances saleswoman.

The city of about two million inhabitants has been plagued by the Boko Haram insurgency for over a decade.

A new faction of the group is also wreaking havoc.

The attack was the third time in a month that the IS-linked Islamic State West Africa Province (ISWAP) group have plunged the entire city of three million into darkness for days by blowing up transmission lines.

"There has been power failure for quite some time, there is total blackout in the city and you know for quite some time we have no light and I have to come and fix my generator," said Joshua Blues, Maiduguri resident.

Reports also say that over the last month the insurgents have carried out a series of attacks on villages leading up to Maiduguri.

Nigeria's President Muhammadu Buhari replaced the heads of the armed forces earlier in January as pressure builds over his response to the security situation.

Large parts of the country are out of government control and an offshoot of Boko Haram - the Islamic State in West Africa Province group- has become even deadlier in the northeast.

Since 2009, at least 36,000 people have been killed in armed conflicts and millions have been displaced.

The violence has spread to neighbouring Niger, Chad, and Cameroon.