MAIDUGURI, Nigeria: The leader of the radical Islamic terrorist network Boko Haram has denied in a video that his group is taking part in any peace talks with Nigeria's government, threatening more violence in a region under near constant guerrilla attack by extremists.

In a video given to a local journalist in northeast Nigeria, Abubakar Shekau also threatens the man who in recent months claimed to be a leader of Boko Haram and said that the group wanted to agree to a ceasefire with Nigeria's security forces.

The re-emergence of Shekau in the video calls into question the motives and affiliations of the other alleged Boko Haram leader and suggests the sect will continue its attacks.

"Whoever kills any of our members should await a grave retaliation from us," Shekau says in the video in the Hausa language of Nigeria's predominantly Muslim north. "We will continue waging war against them until we succeeded in establishing an Islamic state in Nigeria."

A journalist in northeast Nigeria received the video Friday from men he said he didn't know. The journalist began sharing the video with colleagues late Saturday. While The Associated Press could not immediately independently verify the authenticity of the video Sunday, the man on the video looked like Shekau and spoke like the Boko Haram's leader.

The video carried no date, but Shekau directly referenced the activities and claims of a man who has identified himself as Sheikh Mohammed Abdulaziz, a self-proclaimed second-in-command in Boko Haram. In November, a man with a similar voice as Abdulaziz told journalists in a telephone conference call that Boko Haram was willing to enter into peace talks if they were held in Saudi Arabia and involved former military ruler Muhammadu Buhari. However, Buhari refused to take part and no such talks took place as attacks continued.

In January, Abdulaziz told journalists in Maiduguri that a ceasefire would soon emerge that never did.

In the video, Shekau denies knowing Abdulaziz. In the past, Nigeria security forces have used so-called Boko Haram members in sting operations and to sow discord in the group.

"I swear by Allah that Abdulaziz or whatever he is calls himself did not get any authority from me to represent me in any capacity. I do not know him," Shekau says. "And if we per adventure encounter Abdulaziz and his group, I swear by Allah we are going to mete them with the grave judgment that Allah has prescribed for their likes in the holy book."

In the video, Shekau also says the group has had difficulty putting its messages online and blamed government interference for having to now rely on couriers to reach the public. The last Shekau video seen was posted to the Internet in late November.

Boko Haram, whose name means "Western education is sacrilege," has conducted a guerrilla campaign of bombings and shootings across Nigeria's north over the last two years. Boko Haram is blamed for at least 792 killings last year alone, according to an AP count. The group's command-and-control structure remains unclear, though it appears to have sparked several splinter groups.

A group of men claiming to belong to Boko Haram claimed responsibility for the kidnapping of seven French tourists from northern Cameroon late February - a first for the group. Meanwhile, a Boko Haram splinter group known as Ansaru has claimed the recent kidnappings in north Nigeria of a British citizen, a Greek, an Italian, three Lebanese and one Filipino, all employees of a Lebanese construction company called Setraco.

Despite the deployment of more soldiers and police to northern Nigeria, the nation's weak central government has been unable to stop the killings. Meanwhile, human rights groups and local citizens blame both Boko Haram and security forces for committing violent atrocities against the local civilian population, fueling rage in the region.