A serious clash between Burkina Faso's presidential guard and the prime minister has left the west African nation on a political tightrope three months ahead of a key presidential election.

"I shall have done all I can to keep the peace in our country," interim President Michel Kafando recently declared, but he acknowledged being powerless to resolve confrontation.

The former diplomat instead called on "everybody's sense of responsibility... (to) save Burkina from disorder and chaos" before and after the vote in October.

The poverty-striken Sahel nation, whose former president Blaise Compaore was toppled by a popular uprising in October 2014 after 27 years in power, is struggling to get over a crisis triggered by the Regiment of Presidential Security (RSP).

The highly-trained corps in February briefly demanded the dismissal from government of Lieutenant-Colonel Isaac Zida, its second-in-command, who is prime minister in a transitional regime.

Zida, who briefly served as head of state after Compaore was ousted, had called for the RSP to be disbanded in the interest of national security.

- 'False coup' -

The regiment was widely criticised for brutality during the demonstrations against Compaore, when 24 people were killed and more than 600 injured.

On June 28, the government announced that a plot by RSP soldiers against Zida had been foiled, but army officers accused him of staging a "false coup" to keep his job.

Kafando and Zida are due to hand over to a new executive formed after the presidential election scheduled for October 11 to complete a political transition.

Several civil society organisations have accused the authorities of dirty tactics. "The RSP-Zida crisis they're trying to sell us is a cover for a bid to restore the old regime," one statement said.

Whether or not Compaore has any say in events from exile in Morocco, the anti-Zida movement is real and extends far beyond the crack regiment, which civic bodies want disbanded.

Military chiefs have urged Kafando to form a purely civilian government, thus getting rid of Zida, who also serves as minister of defence.

Zida made himself more unpopular in June for overseeing a reform to the military code making it possible to promote a lieutenant-colonel to general "in exceptional circumstances".

"We've had military men who have been heads of state in this country," a top general staff officer told AFP, recalling that Compaore took power as a captain, like his predecessor and one-time comrade Thomas Sankara. "Nobody has tried to give themselves a higher rank."

A senior RSP officer said that to end the crisis, the regiment was "completely placing itself in President Kafando's hands".

"If he doesn't make good decisions or takes too long, we'll be forced to withdraw and let the soldiers do as they want," the officer warned. "We can't calm them down indefinitely."

- 'Call for help' -

Kafando's "call for help", as political analyst Siaka Coulibaly described his plea to the people, could be a bad omen when troops are restless.

Last Sunday, Kafando dismissed security minister Colonel Auguste-Denise Barry in a move widely seen as a step to appease the army. A key supporter of Zida, Barry became an RSP target in its bid to obtain purely civilian rule.

The government took another blow on July 13 when an African regional court overturned electoral legislation that had banned several individuals and political parties linked to Compaore from standing at the polls.

In a binding decision, the Court of Justice in the 15-nation Economic Community of West African States (ECOWAS) upheld suits from seven Burkinabe parties and 13 inviduals protesting at rights violations.

Burkina Faso is affected by "much amateurism in government", worsened by frequent "interference" by civil society, Zida's special advisor Abdoulaye Soma acknowledged.

Uncertainties hang over the planned poll. The former presidential party has designated Eddie Komboigo as its candidate, without knowing whether he can stand.

Compaore's former foreign minister Djibrill Bassole has been expected to run for office, but was barred by military code reforms.

However, Burkina's lawyer in the regional court case, Mamadou Savadogo, pledged that the electoral code would be amended to ensure compliance with the ruling. Kafando has already appointed a council of elders to help.

Presidential candidate and former minister Ablasse Ouedraogo is confident. "We may see trouble here and there, but the political maturity of the Burkinabe people will enable us to see through the transition, with clean and transparent elections.

"Nobody is prepared to head into chaos," he said.