OUAGADOUGOU, Burkina Faso (AP) — West African heads of states denounced extremism during a visit to Burkina Faso's capital Monday, vowing to strengthen cooperation to defeat Islamic militants who carried out two simultaneous attacks in Ouagadougou that killed at least eight people Friday.

Their pledge came as the al-Qaida-linked extremist group based in Mali that claimed responsibility for the attacks released a photo that it says is of a suicide bomber before he detonated his vehicle at the army headquarters.

"We have come to condemn in the strongest possible way these terrorist acts and to say that, whatever the sacrifice, we must do everything so that peace and security reign " said Togo's President Faure Gnassingbe, who is acting chairman of the West African regional bloc ECOWAS.

He and Niger President Mahamadou Issoufou on Monday visited the sites of the extremist attacks, the French Embassy and joint chief of staff offices of the army.

"Terrorism is an international phenomenon that hits no matter where and no matter what. Today it's Ouagadougou, tomorrow is another city, so we must strengthen cooperation because alone one cannot defeat terrorism," said Gnassingbe.

Niger President Issoufou, who is also acting chairman for the regional anti-extremist force, known as the G5 Sahel force, said extremism had no future in the region.

"Its defeat is inscribed in the obsolete and anachronistic nature of the values it claims to defend ... and the despicable and inhuman nature of its barbaric methods," he said.

He praised the G5 Sahel force set up to fight Islamic extremists and the international partners that are helping to fund it.

"We are going to strengthen our operational capacities, intelligence capacities with our allies, and we are sure that with this coalition we are going to militarily defeat terrorism and create the conditions for economic development in the Sahel countries," he said.

The 5,000-strong force combines troops from Burkina Faso, Mali, Niger, Chad and Mauritania.

Several extremist groups have vowed to step up the bloodshed in West Africa in response to the recent deployment of the multinational G5 force.

Among those is the militant group Jama Nusrat Ul-Islam wa Al-Muslimin, known by its acronym JNIM, which on Saturday said it carried out the attacks in retaliation for the killing of one of its leaders in a recent raid by French troops, according to the Alakhbar Mauritanian news agency.

On Monday, the group issued a photo of Yunus al-Fulani, who it named as its suicide bomber.

A car bomb exploded inside the army headquarters and a former Burkina Faso soldier is believed to have participated in the attacks.