A screengrab taken on July 13, 2014 from a video released by the Nigerian Islamist extremist group Boko Haram and obtained by AFP shows the leader of the Nigerian Islamist extremist group Boko Haram, Abubakar Shekau (centre)
Kano (Nigeria) (AFP) - Boko Haram has seized control of a town in northeastern Nigeria, the latest to fall into Islamist hands in the crisis-hit region and an indication of the group's increasing territorial ambitions.
The insurgents have tended to use hit-and-run attacks in the past but the recent seizure of towns suggests a significant shift in strategy, more in keeping with their stated goal of carving out a strict Islamic state in northeastern Nigeria.
Residents who fled the assault on the fallen town of Buni Yadi in Yobe state said attacks began late last month and the insurgents have since taken over the main government building.
The militants have reportedly raised their flag and carried out summary executions, including of two people who were caught smoking cigarettes.
Abdullahi Bego, the spokesman for Yobe's Governor Ibrahim Geidam, could not confirm the executions.
But he told AFP: "As I speak there are no military in Buni Yadi and locals say that Boko Haram come and go as they please.
"So many people from Buni Yadi have fled to the state capital Damaturu," he added.
There was no immediate comment from the military in Damaturu or Abuja.
But residents said the rebels, who massacred dozens of students at a boarding school in Buni Yadi in February and kidnapped more than 200 schoolgirls from neighbouring Borno state in April, had set up roadblocks.
They were also robbing people as they tried to flee.
"I left Buni Yadi yesterday (Wednesday) because it was no longer safe for me and my family," said trader Surajo Muhammad.
The gunmen "shot dead two men for smoking and they also killed a known drug peddler", he added.
Tijjani Bukar, who also fled, reported the same executions.
"I couldn't stay any longer because I came to realise these people have come to stay," he said.
"I thought they would be there for a few days but from our understanding they have turned the town into their (territory)."
The United Nations has confirmed that Boko Haram seized control of the towns of Damboa and Gwoza in Borno state in recent weeks. There are indications that Damboa was retaken by the military in an offensive earlier this month.
Police said their training academy just outside Gwoza in the Liman Kara area was attacked by the insurgents late Wednesday.
"I can't say if there were casualties," national police spokesman Emmanuel Ojukwu told AFP. "We still don't know if they have taken control of the school."
- Significant change -
"The capture and holding of territory presents a significant evolution in Boko Haram's modus operandi," said Ryan Cummings, chief Africa analyst at the South Africa-based crisis management group Red 24.
He told AFP that trend became evident in April, with many districts in the northeast threatened by an Islamist takeover and Nigeria's embattled military struggling to reverse the rebel gains.
A group of soldiers in Borno staged a mutiny this week after being ordered to retake Gwoza on the grounds that they had not been provided adequate weapons to fight the well-armed militants.
Cummings said Boko Haram's recent advances indicated the group was "slowly but surely out achieving its primary goal -- the creation of a caliphate in northern-eastern Nigeria governed under sharia law."
Yobe, Borno and Adamawa states have been under a state of emergency since May last year and reliable information on the conflict has proved difficult to obtain.
Few humanitarian workers are on the ground and the military has sought to restrict the flow of information.
Jacob Zenn, an analyst at the US-based Jamestown Foundation, said the insurgents have systematically destroyed roads and bridges in the northeast, "making it difficult for the Nigerian military to send reinforcements".
Boko Haram is blamed for killing more than 10,000 people since its uprising began in 2009 and their violence has forced more than 600,000 people from their homes, according to the UN.
Cummings said the situation may deteriorate further.
"With the Nigerian military struggling to defend, let alone recapture Boko Haram-held territory, it can be said with little contention that the sect will seek to assimilate further territory," he said in an email exchange.
One possibility was an advance on Borno's capital Maiduguri, he added.