Nigeria's military says Abubakar Shekau, the leader of militant Islamist group Boko Haram, may have died of a gun-shot wound sustained during an assault by government forces on his forest hide-out in north-eastern Nigeria last month. Nigeria analyst Andrew Walker assesses the implications of the claim.
If the death of Boko Haram leader Abubakar Shekau is verified then it is undoubtedly a key milestone in the life of the group which, in almost exactly four years, has murdered thousands in northern and central Nigeria.
Since 2009, the group (whose name roughly translated means "Western education is forbidden" in the local Hausa language) has waged a guerrilla insurgency against the state and a wide array of "soft" targets.
At times, large-scale attacks came almost daily.
Boko Haram believes its war will bring a strident and extreme form of Islamic law to Nigeria.
School children, teachers, the UN, the police, north-eastern traditional leaders, journalists, mobile phone towers, ordinary Nigerians going about their lives have all come under attack.
The group is also reported to have moved to Mali during the conflict there, where it is alleged to have received training from foreign jihadis.
Looking back over the last four years the attacks appear to be almost mini-campaigns, responses by the group to events in Nigeria and outside.
The type of attacks evolved as the group developed, and in some cases occurred in several areas in short succession - evidence the group was controlled by a tight cadre of people, and the cell-like structure of the organisation took direction.
So killing the leadership might possibly have a big effect on how the group is organised and how well it is able to repeat such big campaign attacks in future.
"Might possibly" because what is known for sure about Boko Haram is very scant. Reliable information from Nigeria in general is a rare thing; from a secretive Islamist insurgency even rarer.
Certainly, until Nigerians see more proof, they are unlikely to believe that Shekau is actually dead - the military has claimed they have killed top leaders, even Shekau himself, before.
Shekau appeared in a video circulated to journalists on 12 August, but the military has claimed this was acted by an impostor.
Hundreds of people have written in to the BBC's Hausa Service social media pages to voice their scepticism at the announcement, which coincides with the end of operations carried out by the Joint Task Force (made up of the military and police) against Boko Haram and the launch of a new brigade with special responsibility to tackle the group.
Nigerians on social media are wondering if the announcement could be more to do with this launch and the military's relationship with the federal government, than events on the ground.
It is also unclear what effect the killing of the group's leadership might have on the danger radical militants present to northern Nigeria.
It is true that in recent months the group has been put into abeyance, civilian vigilante groups have reportedly chased them away from Borno state's Maiduguri city.
They were chased to southern Borno, where the military have been concentrating their attacks successfully, says Boko Haram analyst Adam Higazi in a report for think-tank Oxford Analyitica.
Shekau may have been killed in these attacks near the border with Cameroon between 25 July and 3 August, the military says.
But since the period when the army said he could have died, at least 70 people have been killed in a number of attacks across the north.
A bomb went off in the major northern city of Kano on 29 July, killing 15.
Gunmen killed at least 11 in Damboa in Borno state on 17 August.
And, most puzzlingly, gunmen killed at least 44 Muslims praying at a mosque on 11 August, just days after the festival of Eid that marks the end of the Islamic holy month of Ramadan.
Time after time, the group has proven that is never more dangerous than when people believe it is on the back foot.
While it is a political and religious insurgency, Boko Haram could also be said to be a kind of personality cult held together by the reverence its members have for the groups' original leader Mohammed Yusuf, killed by the police in July 2009.
It built itself up to its biggest attacks after coming back to avenge Mr Yusuf's slaying.
Many have voiced fears that the unregulated vigilante group, known as the "civilian JTF", could deepen the conflict and give armed men more to avenge.
If Shekau is dead, three questions remain: Will the power of Mohammed Yusuf's charisma stretch into a third generation of leadership?
Or will northern Nigeria be left with a disparate group of violent and increasingly desperate armed criminals?
Most importantly, will there be any discernible difference between the two?
And if it turns out that Shekau is alive, the question the military will have to answer is: Did one of the world's most dangerous Islamist militants slip through its fingers to continue his vengeance?