Multinational forces fighting the Islamic extremists of Boko Haram arrested five of the group's leaders and freed dozens of captive women and children, Cameroon's government said Saturday.

The raids targeting Boko Haram bases in the northern Madawaya forest earlier this month freed 28 children and at least 18 women, authorities said.

The news came as several West African leaders, French President Francois Hollande, and top British and American diplomats gathered at a summit in the Nigerian capital, Abuja, to discuss regional security and strategies to fight Boko Haram.

Nigerian President Muhammadu Buhari said about $1 billion was needed to help development in the Lake Chad region in order to "eradicate the causes" of terrorism.

Buhari called for rebuilding destroyed infrastructure such as schools, health clinics, roads and bridges, as well attending to displaced people, most of them women and children.

U.S. Deputy Secretary of State Antony Blinken told the gathering that Washington was "deeply committed" to helping the military effort and also reconstruction, but "victory on the battlefield is not enough."

Blinken said it was of paramount importance that Boko Haram be defeated not only militarily but also ideologically. He also called for investigations into multiple claims of human rights abuses against armies involved in the conflict.

The final communique said that a "global approach" was needed to defeat Boko Haram, involving both hard and soft power.

Hollande urged the international community to do more, warning about the humanitarian situations in the countries of the Lake Chad Basin — mainly Nigeria, Niger, Chad and Cameroon — under attack from Boko Haram. He also noted Nigeria's achievements under Buhari in its counterterrorism fight, but said that although Boko Haram had been forced to retreat, it still remained a threat.

Pledging full support of his country against the extremist group, British Foreign Secretary Philip Hammond said it was imperative to maintain the momentum to win the war against Boko Haram and build the right conditions for stability in the region.

Besides the U.S. and the European Union officials, the summit brought together Buhari's counterparts from around the region, including leaders from Benin, Cameroon, Chad and Niger.

In 2014, Boko Haram captured swaths of territory in Nigeria and declared a self-styled caliphate. The next year, it declared allegiance to the Islamic State. Since Buhari became president of Nigeria, the army has stepped up military actions against Boko Haram, leading the president to announce that the Islamist group had been "technically" defeated.

Boko Haram's current, nearly seven-year insurgency has spilled beyond Nigeria's borders. Attacks in Cameroon, Chad and Niger have claimed at least 20,000 lives and forced more than 2.6 million people to flee their homes, including 300,000 children.