OUAGADOUGOU (Reuters) - Eight people including two Burkinabe soldiers have been arrested in connection with an attack by Islamist militants that killed eight security agents in Burkina Faso’s capital on Friday, the country’s prosecutor said.

A Mali-based al Qaeda affiliate called Jama’a Nusrat ul-Islam wa al-Muslimin (JNIM) claimed responsibility for the assault on the French embassy and the army headquarters in Ouagadougou in which eight gunmen were also killed and over 80 people were wounded.

Investigators suspect the attackers received inside help when they targeted a room where leading army officials were supposed to be having a meeting.

“An ex-soldier and two others still on duty are among those arrested by investigators,” prosecutor Maizan Sereme told reporters late on Tuesday. She added that more than 60 victims and witnesses had been questioned.

The carefully planned assault, in which attackers were able to force their way into the army headquarters using rifles, grenades and explosives just after 10 a.m. on Friday, highlighted the precarious security situation across the remote, arid Sahel region where Islamist insurgents operate across borders without detection.

One militant blew himself up inside the army compound during clashes that killed six soldiers and two gendarmes were killed at the embassy. In all, over 60 vehicles and motorcycles were burned and over 80 others were damaged, Sereme said.

Previous high-profile attacks in Ouagadougou and near Burkina Faso’s porous border with Mali were also conducted by allies of al Qaeda in reprisal for Burkina Faso’s participation in a regional fight against the militants.

Al Qaeda in the Islamic Maghreb (AQIM) claimed responsibility for attacks on a restaurant and hotel in Ouagadougou in January 2016 in which 30 people were killed. AQIM merged with other local jihadist groups last year to form JNIM.