Nigerian forces repelled an attack by Boko Haram militants in the northeast city of Maiduguri on Thursday, the military said in a statement, the second such clash in a month.

Blasts and gunfire were heard earlier by residents in the city which is the capital of Borno, the state worst hit by the insurgency aimed at creating an Islamic caliphate in the northeast which has killed more than 30,000 people since 2009.

President Muhammadu Buhari, who took office in 2015 vowing to end the insurgency, has made it a priority to improve security in Africa's most populous country. The issue has become politically charged in the run-up to an election next year which Buhari said he wants to contest.

"Troops of Operation Lafiya Dole have in the late hours of today, Thursday 26 April 2018, successful repelled Boko Haram terrorist incursion in the outskirt of Jidari Polo area of Maiduguri," the military said in an emailed statement.

Boko Haram militants attempted to enter Maiduguri earlier this month, fighting soldiers in an attack in which at least 15 people were killed and 83 injured.

In the course of fighting the latest attack, the military said troops had been supported by the air force, police and other security agencies.

Witnesses had reported a heavy military presence and crowded streets as people attempted to flee to safety.

The general public and residents who fled the area earlier were urged to return home, the military statement said.

The government has been saying since December 2015 that the jihadist group has been defeated but high profile attacks in the last few months - including the kidnap of 111 schoolgirls from the town of Dapchi and a strike in the town of Rann that killed three aid workers - has shown the jihadists remain active.

Nigeria's government last month said it was in talks with Boko Haram, which split into two main factions in 2016, with the aim of securing a permanent ceasefire.

The government has not disclosed which elements of Boko Haram it is in discussions with and it was also not clear which faction carried out the latest attack.

Reuters