LAGOS, Nigeria: As many as 300 people were killed on Monday night in Gamboru Ngala, a border town with Cameroon, when heavily armed Boko Haram insurgents laid siege to the town in Borno State.

The insurgents targeted a local market, where they fired sporadically into the crowd before proceeding to the town to wreak more havoc.

Gamboru, situated along Nigeria-Cameroon border, is the administrative headquarters of Ngala Local Government Area of the troubled Borno State. It is about 200km from Maiduguri, the state capital.

Nigerian federal Senator Ahmed Zannah said the attack lasted about 12 hours, according to the newspaper. The insurgents set homes ablaze and gunned down residents who tried to escape from the flames, reported the paper.

Zannah blamed fighters of Nigeria’s homegrown Boko Haram terrorist network that has claimed responsibility for the kidnapping of 276 teenage girls and is threatening to sell them into slavery.

Boko Haram’s five-year-old uprising has claimed the lives of thousands of Muslims and Christians. More than 1,500 people have died in their attacks so far this year. The insurgents say Western influences are corrupting and they want to impose an Islamic state in Nigeria, a country of 170 million of whom half are Christian.

He revealed that several other persons were also injured in the attack, while almost all the houses and shops in the town were burnt down.

The senator, who spoke on the Hausa service of the BBC, said many people were wounded, while surviving victims had been rendered homeless as thousands of houses and shops were burnt by the rampaging gunmen.

He claimed that the attackers were armed with dangerous weapons comprising armored personnel carriers (APCs), improvised explosive devices (IEDs), petrol bombs, assault rifles and rocket propelled grenades (RPGs).

“The attackers stormed the communities in the night when residents were asleep, setting ablaze houses and shot residents who tried to escape from the fire,” he said.

He added: “About 300 persons were confirmed dead after the incident, with several others injured. Almost all the houses in the communities were destroyed by the hoodlums who threw IEDs at the buildings.

“My brother who was at the scene of the attack told me that the actual number of the dead cannot be ascertained but at least they are up to 300.

Nigerian police offered a $300,000 reward on Wednesday for information leading to the rescue of more than 200 schoolgirls abducted by the rebels.

The mass kidnapping last month by militant group Boko Haram, which is fighting for an Islamic state in northeast Nigeria, triggered an international outcry and protests in Nigeria, piling pressure on the government to get the girls back.

Public anger mounted after locals on Tuesday said another eight girls had been seized from the same remote northeastern area by suspected members of the group.

Police listed six phone numbers in their statement and urged Nigerians to call in with “credible information.”

Boko Haram leader Abubakar Shekau has threatened in a video to sell the girls abducted on April 14 from a secondary school in the village of Chibok “on the market.”

The United States has offered to send a team to Nigeria to help the search efforts.

France on Wednesday offered Nigeria a “special team” to look for more than 200 girls that has triggered global shock and condemnation.

“A special team with all our resources in the region is at the disposal of Nigeria to help in the search and recovery of these young girls,” French Foreign Minister Laurent Fabius told Parliament.

Britain too will send a small team of experts to Nigeria to help respond to the kidnap of more than 200 girls, a Downing Street spokesman said Wednesday.

The team will concentrate on planning, coordination and advice to local authorities rather than operations on the ground to look for the girls.

The team will fly to Nigeria “as soon as possible”, Prime Minister David Cameron’s official spokesman said.

Nigerian President Goodluck Jonathan accepted the offer when the two leaders spoke on the telephone earlier Wednesday.