Abuja - Nigeria and its regional allies on Wednesday called for greater international support to shut down Boko Haram's weapons and funding supply as concern mounted at the group's rapid recent land grab.
The call came after conflicting reports that the militants had seized another town, prompting warnings that Nigeria was losing control of the northeast and violence could spill across borders.
Nigeria's Foreign Minister Aminu Wali said his counterparts from Benin, Chad, Cameroon and Niger recognised the need for a more joined-up approach to curb arms trafficking and spiralling violence during a day of talks on the security crisis.
"(The meeting) called for greater co-operation of the international community to assist in tracking these sources with a view to putting an end to these practices and all forms of illegal transfer of arms and ammunition," he told reporters in Abuja.
Boko Haram grew out of a largely peaceful anti-corruption movement led by Islamic preacher Mohammed Yusuf in northeast Nigeria, turning violent only after his death in police custody in 2009.
But progressively more bloody attacks, including Al-Qaeda-style car and suicide bombings, have led to discussion about the exact nature and extent of their links to the global jihadi network.
The United Nations earlier this year designated Boko Haram an Al-Qaeda-linked group in a move designed to shut down any overseas funding and support.
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Analysts believe the sanctions are largely symbolic, with little or no proven operational links with overseas extremists, despite Boko Haram's leader Abubakar Shekau praising jihadi leaders.
The group's operations have also largely been confined to Nigeria's northeast, where it is thought to have financed its operations mainly through bank robberies, kidnapping and extortion.
Nigeria's soldiers deployed in the region have complained that the militants are better armed, with high-powered assault rifles, rocket-propelled grenades and even armoured personnel carriers.
Some arms supplies are thought to come in via smuggling routes from Libya through Sahel countries, but Boko Haram has also regularly seized weapons and hardware from the Nigerian military.- Another town seized? -
Nigeria's neighbours vowed to play a greater role in tackling the Islamists after the abduction of more than 200 girls from their school in northeast Nigeria in April, which caused global outrage.
International intelligence and surveillance specialists and equipment were sent to Abuja to help trace the missing teenagers, 219 of whom are still being held captive.
But nearly five months on, Western diplomats have indicated that there has been little progress, despite a claim from Nigeria's military that they had located the girls.
Nigeria has repeatedly played up what it says is the regional aspect of the insurgency, blaming foreign fighters and overseas funding for the violence.
But while some foreign mercenaries may be in the guerrilla ranks and there have been attacks beyond Nigeria's borders, some analysts say the conflict remains largely "local".
Any wider military response could internationalise the conflict, they have warned.
Boko Haram has in recent weeks taken and held swathes of territory in northeast Nigeria in a departure from their previous hit-and-run tactics.
On Monday, the militants reportedly took over the town of Bama, 70 kilometres (45 miles) from the Borno state capital, Maiduguri, sending hundreds of soldiers fleeing.
The military disputes the claims, but the fighting has raised fears that Boko Haram has the city in its sights and aims to make it the centre of a separate, hardline Islamic state.
"We live in fear of a possible Boko Haram attack on Maiduguri because of the speed with which they are taking over towns and villages," said resident Babagana Kolo.
The Nigeria Security Network of analysts said Nigeria's northeast was "on the brink" of coming under Boko Haram control, which could see parts of Cameroon being overrun and spark a humanitarian crisis.
Meanwhile, residents, a police officer in the Cameroon town of Amchide and a Nigerian lawmaker said the militants took control of the town of Banki in Borno state on Tuesday.
"From the information that I have received from the people in Banki and Amchide, Boko Haram has taken over Banki," Borno senator Ahmed Zannah told BBC radio's Hausa language service.
"More than 200 Nigerian soldiers fled to Amchide from Banki when Boko Haram headed towards the town."
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