Two top generals accused of masterminding the plot, Gilbert Diendere and Djibrill Bassole, were cheered by supporters as they arrived at the court in the capital Ouagadougou.

Security was high, with forces guarding a 200-metre (yard) cordon around the military tribunal. Traffic was blocked, mobile phones banned and people entering the zone were searched.

Bassole and Diendere -- key allies of former president Blaise Compaore who was chased from power in October 2014 -- are among a total of 84 people on trial, including 66 military officials and 18 civilians.

They face a variety of charges including treason, undermining state security and murder over the coup launched in September 2015 by Compaore's old presidential guard against the transitional government that took power after the veteran leader's fall.

The elite unit known as the RSP briefly took the country's leaders hostage before the coup was thwarted by street protesters and support from the army which attacked the plotters' barracks.

Fourteen people died and 270 were injured in the unrest in the former French colony.

The defendants risk heavy penalties, including the death sentence, which has not been used in Burkina Faso for 30 years.

The Burkinabe Movement for Human and People's Rights (MBDHP) described the case as a "life-size test of the credibility of the Burkinabe judiciary", often accused of being under the control of those in power in a country blighted by numberous coups and mutiny since independence in 1960.

Some analysts say the trial could also shed light on other non-resolved high-profile cases in Burkina Faso, such as the assassination of Thomas Sankara in 1987 or journalist Norbert Zongo in 1998, where the names of Diendere or Campaore's presidential guard often come up.