Boko Haram has claimed responsibility for an attack on a key military barracks in Nigeria, in a new video obtained on Monday by AFP that warns of further bloodshed, including against civilians.
"We carried out the attacks in Maiduguri (on March 14)," said a man dressed in white, wearing black headgear and carrying an assault rifle, claiming to be the group's leader, Abubakar Shekau.
The man appeared younger, thinner and with different mannerisms from older videos, which could prompt fresh questions about whether the militant leader, who had previously been reported killed, is still alive.
The United States has declared Shekau a global terrorist and put a $7 million (5.1-million-euro) bounty on his head. Nigeria has separately offered 50 million naira ($300,000) for information leading to his capture or death.
He was reported to have been killed in a gun battle in northeast Nigeria between July 25 and August 3 last year, although a man resembling him has featured in a number of videos since then.
Nigeria's military has yet to confirm officially whether Shekau is still alive and defence spokesman Chris Olukolade has said that whoever was making the claims in the videos was immaterial.
"That's not the issue in this matter. They're all terrorists," he told AFP in a March 14 interview.
In the latest video, which was obtained via the same channels as previous statements, the man claiming to be Shekau speaks for 37 minutes in the local Hausa and Kanuri languages, as well as Arabic.
Footage then follows showing what appear to be heavily armed Boko Haram fighters arriving in pick-up trucks and firing on the Giwa barracks in Maiduguri with assault rifles and rocket propelled grenades.
- Claims of ill-treatment -
Hundreds of suspected Boko Haram fighters have been held at the barracks in the capital of northeastern Borno state in conditions that have been strongly criticised by international rights groups.
The video shows hundreds of people, most of them young men in civilian clothes but also some women, apparently running away from the compound.
Boko Haram claimed in the video that they freed about 2,000 of their brothers in arms, some of whom recounted at length their experience at the facility, alleging torture by the military.
"We launched the Maiduguri attacks and killed infidels in Giwa barracks," said the man who insists several times that he is Shekau, adding a warning about members of the public who have joined civilian vigilante groups against them.
"There are only two groups of people in the world. There are either those with us or those on the other side, which I'll kill once I spot them. This is my only focus now," he said.
"This is Shekau speaking... By Allah, I will slaughter you. I'm not happy if I don't slit your throats. I'll slaughter you, I'll slaughter you, I'll slaughter you."
The video repeats claims made in a previous video obtained on February 19 about Boko Haram members killing a prominent Muslim cleric who had criticised the group and threatening to attack oil wells in southern Nigeria.
"We are not fighting the north, we are fighting the world. And you will see us fighting the world. This is our job," he added.
- Upsurge in violence -
Boko Haram wants to create a separate Islamic state in northern Nigeria and has been blamed for thousands of deaths since 2009.
Nigeria's military imposed a state of emergency in three northeastern states in May last year in an attempt to stop the bloodshed but violence has continued.
This year, more than 700 people have been killed already, most of them civilians in remote rural areas, while tens of thousands have fled their homes.
Nigeria's military claims that measures introduced to prevent the militants from seeking safe haven outside Nigeria, notably in northern Cameroon, are the reason for the upsurge in violence as the group is lashing out.
Top brass said the Giwa barracks attack was a sign of desperation and an indication that Boko Haram's ranks were depleted.
Nigeria's national security adviser last week announced "soft power" measures designed to complement the military offensive, including "de-radicalisation" programmes for Boko Haram suspects and closer cooperation with local people.
The measures were seen as a recognition that Nigeria had realised that force alone could not end the crisis.