African leaders have pledged to wage "total war" on Boko Haram, the militant Islamist group who kidnapped more than 200 schoolgirls in Nigeria.

The group is "acting clearly as an al-Qaida operation", the Nigerian president, Goodluck Jonathan, said. Speaking at a summit of African leaders in Paris, he said the threat posed by the militant group was now an international problem.

The French president, François Hollande, who is hosting the talks, said Boko Haram had links to al-Qaida and other terrorist organisations.

"Boko Haram is a major threat for all of western Africa and now central Africa with proven links to AQIM [al-Qaida in the Islamic Maghreb] and other terrorist organisations," he said.

"A comprehensive plan needs to be put in place from exchanging information to coordinating action and controlling borders."

The president of Chad, Idriss Déby, said: "There is determination to tackle this situation head on" and "to launch a war, a total war on Boko Haram".

Speaking before the talks in Paris, William Hague urged west African nations to put aside their differences to end rebel attacks.

"This is one sickening and terrible incident, but they continue almost every day to commit terrorist attacks and atrocities of other kinds, so they have to be defeated in the region," the UK foreign secretary said. "That requires a better regional strategy among the African countries, but with our support."

He said Nigerian security forces were not well structured to deal with the threat posed by Boko Haram.

"We can help with that, which is why we are offering to embed military advisers within the Nigerian headquarters," he said. "Nigeria has the main responsibility and must be the leading nation in tackling this and that includes to mount an effective security response and improve development."

The presidents of Nigeria, Cameroon, Chad, Niger and Benin were invited to the meeting in Paris, with representatives from France, the UK, the US and the European Union.

Hague said West African countries should set up a joint intelligence "fusion cell" to pool information in the hunt for the missing girls. "There are many borders here and they are porous borders," he said. "We need all of those countries to be bringing together their intelligence and information. This is very relevant to finding the schoolgirls, not just to the long-term defeat of Boko Haram."

The UK and US have offered help to Nigeria's search operation, and experts are already in the country. An RAF surveillance aircraft and a military team have also been offered.

On Friday the Nigerian president, Goodluck Jonathan, who has been criticised for a slow response to the abduction, cancelled a visit to the girls' home town for security reasons.

Relatives in Chibok were angry at the cancellation, saying they had no confidence that the government was doing everything possible to find the girls.

Allen Manasseh, whose 18-year-old sister Maryamu Wavi was abducted, said: "You begin to question what could be more important to the president than the lives of these students.

"The parents were hoping he would come with some information for them about where the girls may be and what efforts are being done to recover them, but instead to be told he is not coming was not easy for them. It's not an easy thing to have a missing child."

In London, about 80 protesters delivered a petition to Downing street calling for the government to do more to defeat Boko Haram.

"We're here today to call the international community to bring back our girls," said the march organiser, Amour Owolabi.

"Terrorism isn't a local issue and our government cannot deal with it alone. We need the international community to come and support us in making sure that things like this do not happen again."

Hague has said broader development will be needed in the region to support a long-term defence against Boko Haram. "More will need to be done in the north of Nigeria in terms of clean water, healthcare, education and so on," he said.

The talks in Paris take place as reports suggest a fresh attack in Cameroon may have been the work of Boko Haram rebels. A Chinese plant in the north of the country was attacked on Friday night, injuring one person and leaving 10 unaccounted for.

The Chinese state news agency, Xinhua, said the attackers had not been identified, but Reuters reported that the local governor said they were suspected to be Boko Haram rebels.

Waza is 12 miles from the Nigerian border, close to the Sambisa forest which is a stronghold of Boko Haram who are believed to be holding the girls there. The militant group has killed thousands in Nigeria during a five-year insurgency for an Islamist state which threatens to destabilise the wider region.

The attack follows news that a British-born man who served in the Nigerian army has been arrested on suspicion of being a ringleader of Boko Haram. Aminu Sadiq Ogwuche is believed to have played a key part in the rebel group's bomb attacks which killed 105 people in Nigeria last month.