- Defense Ministry: Troops have killed a man who's been acting as leader of Boko Haram
- He "has been acting or posing on videos as the deceased Abubakar Shekau," it said
- The military has claimed several times to have killed Boko Haram chief Abubakar Shekau
- President Jonathan: Nigeria "knows too well the destructive effects of terrorist activities"
Nigerian forces battling the Islamist terror group Boko Haram have killed a man suspected of acting as the group's leader, Nigeria's Defense Ministry said.
The soldiers and Boko Haram militants clashed several times in the past week in communities around the city of Maiduguri in the country's northeastern Borno state, the ministry's statement said.
"In the course of those encounters, one Mohammed Bashir who has been acting or posing on videos as the deceased Abubakar Shekau, the eccentric character known as leader of the group, died," it said.
"Since the name Shekau has become a brand name for the terrorists' leader, the Nigerian military remains resolute to serve justice to anyone who assumes that designation or title."
The Nigerian military has touted Shekau's death several times, only to retract its claim after he appeared alive and well in propaganda videos.
Several other Boko Haram fighters also died in the latest fighting, the Defense Ministry said, and a number were captured along with their equipment.
Another 135 militants also surrendered to Nigerian troops in the Biu area, southwest of Maiduguri, it said.
Jonathan: Destructive effects
Nigeria's President Goodluck Jonathan told a meeting of the U.N. Security Council on Wednesday that Boko Haram shared a common agenda with other terror groups such as ISIS and al Qaeda -- that being "to unleash terror, mayhem, destruction, and instability around the world" -- but that Nigeria was working hard to root out the group.
"Nigeria knows too well the destructive effects of terrorist activities," he said.
"Over the past five years, we have been, and are still confronting threats posed by Boko Haram to peace and stability predominantly in the North Eastern part of our country.
"The costs are high: over 13,000 people have been killed, whole communities razed, and hundreds of persons kidnapped, the most prominent being the mindless kidnap of our innocent daughters from Chibok Secondary School, in North East Nigeria."
The terrorist group abducted an estimated 276 girls in April from the boarding school in Chibok. Dozens escaped, but more than 200 are still missing.
Nigerian government officials and the International Committee of the Red Cross have had talks with Boko Haram about swapping imprisoned members of the Islamist terrorist group for the girls, a source involved in the negotiations told CNN last week, but hurdles remain.
Show of defiance
Boko Haram was born 12 years ago, led by a charismatic cleric named Mohammed Yusuf who was pushing for a pure Islamic state. Yusuf was killed by police in 2009, with Abubakar Shekau taking over the group.
In recent years, its attacks have intensified in an apparent show of defiance amid the nation's military onslaught. Its ambitions appear to have expanded to the destruction of the Nigerian government.
Much of this violence has been in Yobe, Kano, Bauchi, Borno and Kaduna states in the country's north and east, though the national capital, Abuja, has also been hit.
The name "Boko Haram" translates to "Western education is sin" in the local Hausa language. The militant group is trying to impose strict Sharia law across Nigeria, the most populous country in Africa.