An official stands in front of relief materials at a camp for displaced people in Maiduguri in Borno State January 19, 2015. [Photo/Agencies]

MAIDUGURI, Nigeria - Boko Haram insurgents attacked the outskirts of Maiduguri in northeast Nigeria on Sunday, security sources said, their second assault in a week on a city they hope to make the capital of a breakaway Islamist state.

At least eight people were killed as the militants clashed with soldiers, witnesses and a hospital source said, but the military later said the attack had been repelled.

"There is heavy gunfire going on. Everybody is panicking and trying to flee the area," Idris Abubakar, a resident of Polo suburb on the southwestern outskirts of the city, said.

The insurgents, who arrived in several armed pick-up trucks and on motorbikes, attacked three places in the south of Maiduguri at around the same time, a security source said.

Troops backed by vigilantes had pushed them out of the southeastern outskirts of the city, a spokesman for a local pro-government vigilante group said.

Resident Babagana Lawan said a grenade fell on his house, killing his brother and two factory workers living with him.

In a separate incident in the town of Potiskum, 230 km (140 miles) west of Maiduguri, a suicide bomber blew himself up outside the house of federal legislator Sabo Garbu, killing 10 people, two security sources told Reuters. Garbu was unhurt.

And a suicide bomb attack at a mosque in Gombe town, 300 km (185 miles) southwest of Maiduguri, by a male and a female suicide bomber on a motorbike, killed five people and wounded eight, said a spokesman for National Emergency Management Agency (NEMA) in Gombe.

Growing Boko Haram violence is a big problem for President Goodluck Jonathan, who stands in a presidential election on Feb 14 that analysts say is too close to call.