Ouagadougou - Burkina and French investigators on Monday pushed ahead with a probe into deadly jihadist attacks last week suspected to have aimed at a major anti-terror meeting.
Forensic teams were at work at the scenes of last Friday's twin attack in Burkina Faso's capital, Ouagadougou, and two suspects were being questioned, sources said.
The operation, using guns and a car bomb, aimed at the country's military headquarters and the French embassy.
Nine assailants and seven soldiers were killed and at least 80 people were injured, according to a government toll. The operation was claimed by the Group to Support Islam and Muslims (GSIM), led by the Malian jihadist Iyad Ag Ghaly.
One of the two suspects is believed to have played a key role in the operation, Burkinabe investigators said, adding that clues the attackers had information from within the armed forces "are starting to be confirmed".
The attack on the military headquarters appears to have been aimed at a scheduled meeting of the so-called G5 Sahel - a French-backed group of five countries fighting jihadism in the volatile Saharan region.
The room in the complex where the meeting was to have taken place was wrecked by the car bomb - however, the venue of the meeting was swapped at the last minute, which prevented carnage.
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A team of 10 French experts have arrived to support the inquiry, including counter-terrorism specialists, according to French police and judicial sources.
President Mahamadou Issoufou of Niger and Togelese President Faure Gnassingbe arrived on Monday for talks with Burkinabe counterpart Roch Marc Christian Kabore.
Issoufou is current head of the G5 Sahel, which comprises Burkina Faso, Chad, Mali, Mauritania and Niger, while Gnassingbe is current chairman of the West African regional bloc ECOWAS, the Economic Community of West African States.
Burkina Faso has been the target of jihadist attacks since 2015.
On August 13 last year, two assailants opened fire on a restaurant on the capital's main avenue, killing 19 people and wounding 21. No one has so far claimed responsibility for it.
On January 15, 2016, 30 people - including six Canadians and five Europeans - were killed in a jihadist attack on a hotel and restaurant in the city centre.
GSIM also claimed responsibility for a February 21 attack near the border with Niger which left two French soldiers dead and a third injured in an area which is believes to shelter jihadists.
