Twelve people including a senior army officer are in custody in Burkina Faso after a suspected plot to "destabilise institutions" was uncovered this week, Armed Forces Minister Aime Barthelemy Simpore said on Thursday.
Fifteen people have been arrested since Monday, comprising "two officers, seven non-commissioned officers, a senior officer and five civilians," General Simpore said after a cabinet meeting.
Of these, two civilians and a soldier have been released after giving preliminary testimony, leaving 12 in preventive detention, he said.
Simpore said the arrests were ordered by prosecutors at the military tribunal in the capital Ouagadougou over a "suspected attempt to destabilise the institutions of state".
The impoverished landlocked West African country has a long history of coups and is battling a jihadist insurgency that swept in from neighbouring Mali in 2015.
The conflict has claimed at least 2,000 lives, according to an AFP tally, and forced 1.5 million people from their homes, according to the national emergency aid body CONASUR.
Investigators received a tipoff from a soldier "who is believed to have been contacted by a group of individuals, (wanting him) to join them to carry out acts to destabilise institutions," the minister said.
"We ask the country to remain calm and for people to go about their business while prosecutors pursue their enquiries and issue their report," he said.
Eight soldiers were arrested on Monday, including a senior officer, Lieutenant-Colonel Emmanuel Zoungrana, who had been commanding anti-jihadist operations in country's badly hit western region, security sources told AFP earlier this week.
One of the sources said "suspicions of a destabilisation plot with foreign ramifications" had hung over Zoungrana and several soldiers since protests in November.
Hundreds of demonstrators took to the streets on November 27 over the government's failure to stem the insurgency. Nearly a dozen people were injured in clashes between protestors and police.
Public anger rose after 57 people -- including 53 gendarmes -- were killed when hundreds of jihadists overran a base in northern Burkina Faso earlier in November.