Ouagadougou - A former Burkina Faso soldier may have participated in Friday's simultaneous attacks by al-Qaeda-linked extremists on the army headquarters and heavily-guarded French Embassy in the capital, killing eight soldiers and injuring more than 80 others.The government has launched an investigation and French military experts are expected in Ouagadougou later Sunday to help with the probe, according to a government statement.One of the killed soldiers is believed to have been fired from the army after a 2011 mutiny and may actually have been an assailant, a person close to the investigation told The Associated Press. Many of the attackers were wearing army uniforms, according to witnesses, and some were from Burkina Faso, including two men arrested in connection with the attack, said the official who spoke on condition of anonymity because he was not permitted to speak to the press.The attack on the army headquarter was aimed at a conference room, narrowly missing a meeting of top officers, which would have "beheaded" the military leadership, according to Security Minister Clement Sawadogo.An al-Qaeda-linked group based in Mali claimed responsibility Saturday for the dual attacks.Militant group Jama Nusrat Ul-Islam wa Al-Muslimin issued a message late Saturday saying it was behind the attacks, according to the Mauritanian news agency Alakhbar which often carries claims of responsibility by jihadi groups for attacks in West Africa.The extremist group carried out the dual attacks in Burkina Faso in retaliation for the killing of one of its leaders in a recent raid by French troops, reported the agency.KEEP UPDATED on the latest news from around the continent by subscribing to our FREE newsletter, Hello Africa.FOLLOW News24 Africa on Twitter and Facebook.The group's formation was announced in a video in March 2017 as a merger of three extremist groups: the al-Qaeda-linked al-Mourabitoun, Ansar Dine and al-Qaeda in the Islamic Maghreb. It has positioned itself as the al-Qaeda branch in Mali, and Islamic State in the Greater Sahara, and has also claimed attacks in Mali and Niger.Several extremist groups have also vowed to step up the bloodshed in West Africa in response to the recent deployment of the multinational G5 Sahel force. The 5 000-strong force combines troops from Burkina Faso, Mali, Niger, Chad and Mauritania to battle extremism in the region.Officials haven't commented yet on the claim of responsibility, but Burkina Faso's minister of communications on Saturday said that the assailants could be members of a "sleeping jihadist cell" that has been in Ouagadougou for some time.Burkina Faso's northern border region near Mali is the home of Ibrahim Malam Dicko, an extremist preacher who has claimed responsibility for recent deadly attacks on troops and civilians. His association, Ansarul Islam, is considered a terrorist group by Burkina Faso's government.As residents held special prayers calling for peace, the capital remained on edge Sunday.Three people tried to break through the security barricades at the presidential palace around 4 a.m. Sunday, said army spokesman Colonel Jean Luc Diasso. One of the men was killed while trying to grab weapons from security forces, while the other two fled, he said. The three were believed to be robbers, Diasso said, but the event increased the general mood of insecurity.Later Sunday Security forces fired warning shots near the army joint staff headquarters when people tried to approach the barricades set up to keep residents away from the site of the attacks.The army released the names of the eight members of the security forces killed in the simultaneous attacks, including a senior officer. State funerals will be held at a later time, according to the government.This was the third large-scale attack by extremists on Ouagadougou since January 2016 when 30 people were killed at a popular cafe. In August 2017, 18 more people were killed at a Turkish restaurant. Friday's attack targeted the military's headquarters, showing the extremists are going for hard targets.