PARIS (AFP) - Nigeria and its neighbours on Saturday vowed to work together to combat Boko Haram in what Cameroon President Paul Biya described as a declaration of war on the Islamic militants.

Meeting in Paris, Nigerian President Goodluck Jonathan and his counterparts from Benin, Chad, Cameroon and Niger approved an action plan designed to counter an organisation blamed for 2,000 deaths this year alone and which has caused global outrage with its abduction of more than 200 schoolgirls.

Just hours ahead of the summit, the Islamists carried out another brazen attack, this time killing one Chinese worker and kidnapping 10 others in Cameroon - underlining the regional threat posed by the group.

"We have seen what this organisation is capable of," French President Francois Hollande said at the close of the half-day summit here.

"They have threatened civilians, they have attacked schools and they have kidnapped citizens of many countries. France in particular has been a victim of it.

"When more than 200 young girls are being held in barbaric conditions with the prospect of being sold into slavery, there are no questions to be asked, only actions to be taken," Hollande added.

The action plan would involve coordination of surveillance efforts, the sharing of intelligence and joint efforts to secure the porous borders in the region, Hollande said.

The West African countries have also been promised help in the form of surveillance tools and expert advice from Britain, France and the United States as they seek to combat a group that Hollande said had forged links with terrorist groups all over Africa.

"Religious intolerance has no place in Africa," said Benin President Thomas Boni Yayi.

Nigeria's Jonathan, who has been criticised for what many see as a lacklustre response to the girls' abduction, said he was totally committed to finding them and returning them to their distraught families.

"We are totally committed to finding the girls, wherever they are," Jonathan said.

"We've been scanning these areas with surveillance aircraft," he added, saying Nigeria had deployed 20,000 troops to find the girls.

"Boko Haram is no longer a local terror group," he said. ""From 2009 to today it has changed and can be described as Al-Qaeda in western and central Africa."

The pressure on the leaders in Paris to come up with concrete steps to address the crisis had been intensified overnight when Boko Haram gunmen launched an attack in Cameroon. Militants stormed an encampment used by Chinese road workers late on Friday in a region of northern Cameroon just across the border from the town where they abducted the girls a month ago.

"The Boko Haram militants were heavily armed, they came in five vehicles," an official in Waza, a town near the site of the attack, told AFP on condition of anonymity. He said the camp where the Chinese road workers stayed was usually guarded by soldiers from Cameroon's elite Rapid Intervention Battalion, but many of the troops were in Yaounde for a military parade.

"Cameroonian soldiers retaliated and the fighting lasted until 3:00 am (0200 GMT)," said a local police chief. He said one Chinese worker was killed and 10 others had been missing since the attack and were believed kidnapped by the Boko Haram gunmen.

A source close to the Chinese embassy in the Cameroonian capital Yaounde spoke of 10 missing and one wounded but would not confirm or deny whether one had been killed.

Nigeria has been under pressure to step up cooperation with its neighbours in the fight against Boko Haram for some time. But efforts on that front have been hampered by the frosty state of relations with Cameroon, with which Nigeria has a long-running territorial dispute.

Jonathan played down the extent of the differences but admitted that there was a need for a joint force that could engage in pursuit of militants across national borders.

British Foreign Secretary William Hague told reporters just before the summit that the countries in the region had to forge a "strategy to defeat Boko Haram more broadly" as well as resolving the case of the missing girls.

"This is one sickening and terrible incident but they continue almost every day to commit terrorist acts and atrocities," Hague said.

"There are many borders here and they are porous. This is very relevant to finding the schoolgirls. We want to see the countries in the region working together in creating an intelligence fusion cell," Hague said.

Among the resources already put at Nigeria's disposal have been US drones and surveillance aircraft. Experts from Britain, France and the US are advising Nigeria on its counter-terrorism strategy. France has direct experience of dealing with Boko Haram having recently secured the release of a French family that was kidnapped by the group in Cameroon and then held in Nigeria for two months.

Paris also has troops deployed on peacekeeping duty in the Central African Republic and in Mali, where it sent a force last year to combat Al Qaeda-linked militants who had seized control of much of the north of the country.

Although the French believe that the intervention in Mali inflicted significant damage on groups such as Al-Qaeda in the Islamic Maghreb (AQIM), military planners remain concerned about the implications of potential alliances being forged between militants across the deeply unstable region.