Cameroon said Wednesday its forces have freed a German hostage kidnapped six months ago in Nigeria by Boko Haram, as African leaders appealed to the United Nations for support in fighting the Islamist militants.  

"A special operation led by Cameroonian armed forces along with security services of friendly nations succeeded this night (Tuesday) in freeing Nitsch Eberhard Robert, a German citizen abducted in Nigeria in July 2014 by the Boko Haram sect," the Cameroon presidency said in a statement.

Boko Haram has claimed a massive attack feared to be the worst in its six-year insurgency and threatened Nigeria's neighbors, as talks began for a regional response to the militants and fears grew of further violence.

The confirmation from Boko Haram leader Abubakar Shekau came as no surprise after multiple eye-witness accounts of the attack on Baga, which is thought to have killed hundreds, if not more.

Cameroonian troops fought "heavy clashes" Tuesday with Boko Haram militants near the border with Nigeria as a security summit kicked off in Niger on a regional plan to stop the Islamist fighters. 

Boko Haram insurgents from neighboring Nigeria attacked the far northern Cameroon border village of Bonderi, a source told AFP, adding that "it's too early to give a casualty toll".

Hundreds of people from four villages near the devastated Nigerian town of Baga have been forced to flee after a warning from Boko Haram militants, witnesses and community leaders said Tuesday.

News of the exodus from Kekenu, Budur, Yoyo and Mile 90 villages came as Niger hosted a meeting on how to fight the rebels as concern mounted at the threat to regional security.

Nigeria was on Tuesday awarded $8.1 million in funding for a final push to eradicate polio, as it nears six months without a case of the disease.

Rotary International, which is working with the World Health Organization (WHO) to wipe out the virus, said the money would go towards vaccination, research and surveillance programs.

The U.N. Security Council urged central African countries on Monday to step up plans for a multinational force to fight Boko Haram, in its first overall response to the threat posed by the Nigerian jihadists.

The council issued a 13-point statement strongly condemning attacks by Boko Haram, in particular those involving children used as suicide bombers, and demanded an end to the violence.

When Kofi Annan, the former U.N. secretary general, was in Abuja last week, he urged all presidential candidates and parties to rise above the personal and debate the issues that matter.

But the message appears to have gone unheeded, with fresh attacks from the ruling Peoples Democratic Party (PDP) against Muhammadu Buhari, from the main opposition All Progressives Congress (APC).

Boko Haram freed two dozen hostages after a mass abduction by its militants in Cameroon, as Chad prepared Monday to engage in the international battle against the extremist group.

Twenty-four of the 80 people taken hostage by Boko Haram in the north of Cameroon Sunday were released as Cameroonian armed forces pursued the Islamist extremists, according to a government source.

Boko Haram fighters from Nigeria on Sunday kidnapped at least 60 people in a new attack in northern Cameroon in which some people were killed, police said.

The Islamist militants "burst into two villages in the Tourou area... They torched houses and left with around 60 people. Most of them were women and children," a police officer told Agence France-Presse.

A suicide bomber killed four people and wounded dozens Sunday in an attack at a bus station in Potiskum, northeastern Nigeria, police and hospital sources told AFP.

The town has come under frequent attack by Boko Haram militants and was the scene last Sunday of a bombing in a crowded market carried out by two female suicide attackers, one believed to be aged around 15.