Nigerian President Goodluck Jonathan on Saturday defended his decision to cancel a visit to the town of Chibok from where more than 200 schoolgirls were kidnapped by Boko Haram Islamist militants more than a month ago.

"What is of interest now is to locate the girls. The girls are not in Chibok," said the Nigerian leader, whose last-minute cancellation of a visit to the town, ostensibly for security reasons, was widely criticized.

A Cameroonian soldier was killed and 10 Chinese nationals were feared kidnapped after an overnight attack in northern Cameroon believed to have been carried out by Boko Haram militants from Nigeria, police said Saturday.

"Boko Haram Islamists attacked a camp (of road workers)... Ten Chinese cannot be found since the attack. We think they have probably been kidnapped," a local police chief said on condition of anonymity.

Mexican film star Salma Hayek and French actress Julie Gayet branded signs saying #BringBackOurGirls on Cannes' red carpet Saturday, joining global calls to free 223 schoolgirls kidnapped by Islamist militants in Nigeria.

Hayek and Gayet posed with the signs for a long time before climbing up the steps to the festival hall in the French Riviera resort.

Nigeria and its neighbors vowed Saturday to join forces against Boko Haram under an accord described as a declaration of war on the Islamic militants holding more than 200 schoolgirls.

Meeting in Paris, Nigerian President Goodluck Jonathan and his counterparts from Benin, Chad, Cameroon and Niger approved an action plan to counter an organization that has been blamed for 2,000 deaths this year as well as last month's abduction of the schoolgirls from northeastern Nigeria.

Nigerian President Goodluck Jonathan meets with leaders of neighboring states in Paris on Saturday for talks aimed at forging a common strategy against Islamist militants holding more than 200 schoolgirls.

At a half-day summit hosted by French President Francois Hollande, Jonathan will be pressed to seek much closer cooperation with neighboring Cameroon, Niger, Chad and Benin in the fight against Boko Haram.

A group of gunmen razed two schools in Bauchi state, northern Nigeria, where Boko Haram gunmen previously attacked a girls' school, a police spokesman said on Thursday. 

Dozens of gunmen in cars and on motorcycles stormed the neighbouring villages of Shadarki and Yelwan Darazo, setting two primary schools ablaze, one in each village, said officer Haruna Mohammed. 

Nigeria's President Goodluck Jonathan will visit a northeastern town where more than 200 schoolgirls were kidnapped by Islamic militants, with international criticism mounting of his response to the crisis. 

A senior government official told Agence France Presse that the head of state would be in remote Chibok in Borno state on Friday before flying to Paris for a regional security summit to discuss the Boko Haram threat. 

U.S. officials on Thursday slammed Nigeria's "slow" response to the kidnapping of more than 200 schoolgirls by Islamic militants and renewed criticism of its military over its human rights record.

Democratic senator Robert Menendez, chairman of the Senate Committee on Foreign Relations, said Nigeria had been "tragically and unacceptably slow" to deal with the crisis, despite offers of assistance from the United States and other countries.

A suspect wanted over the deadliest-ever attack in Nigeria's capital -- a blast blamed on Boko Haram Islamists -- has been arrested in Sudan, a source close to the case said Thursday.

Aminu Sadiq Ogwuche was detained on Tuesday as he tried to get a visa from the Turkish embassy in central Khartoum, the source told Agence France Presse, requesting anonymity.

Relatives of more than 200 schoolgirls held hostage by Boko Haram on Thursday called for their unconditional release, after Nigeria's government ruled out a prisoner swap with the extremists.

Boko Haram leader Abubakar Shekau indicated in a video this week that he could release the 223 girls now held for more than a month in exchange for militant fighters in custody in Nigerian jails.