The French embassy, according to Reuters, said Burkina Faso's military police did nothing on Nov. 18 as hundreds of protesters violently attacked the embassy, throwing stones and other projectiles at its walls.
Some of the protesters marched to the gates of the French military base, demanding soldiers to leave.
Some of the officers charged with protecting the embassy were captured on video playing cards as the protest unfolded, the letter said.
Burkina Faso's chief of staff of the national gendarmerie Evrard Somda said the officers posted outside the embassy were not equipped to handle the protest and that he was waiting for orders from authorities to send in reinforcements, which took several hours.
As for the gendarmes who were playing cards, he said he had seen the video and was handling the problem internally.
A diplomatic source said the embassy sent a letter to authorities over the weekend asking to respect international conventions on the protection of diplomatic enclaves and to increase security around the embassy.
A spokesperson for Burkina Faso's foreign ministry, Celine Ilboudo, said it had not yet received the Nov. 19 letter but confirmed the French embassy had previously sent mail about the issue.
The embassy has submitted several requests of this kind and the foreign ministry has assured demands would be met, the source told Reuters on Monday.
Demonstrators already targeted the French embassy in early October, the day after Burkina Faso's military leader Ibrahim Traore announced he had overthrown the government in the country's second coup this year.
Protesters set the French embassy on fire after Traore claimed the leader he ousted, Paul-Henri Damiba, had taken refuge at a French army base, which France denied.
"The events suffered in October and November are susceptible to be repeated in the coming days, if nothing is done," said the French embassy letter dated Nov. 19.
It requested security reinforcements at the French embassy, the ambassador's residence and French schools and cultural establishments in capital Ouagadougou and in the city of Bobo-Dioulasso.