The leaders of a military coup in Guinea promised on Monday to set up a transitional government of national unity after ousting President Alpha Conde and dissolving his cabinet.

Sunday’s coup, in which Conde and other top politicians were detained or barred from travelling, is the third since April in West and Central Africa, raising concerns about a slide back to military rule.

The takeover was widely condemned by international powers, placing pressure on the new military leaders to offer a plan beyond the toppling of the old order, and to reassure investors that Guinea’s significant ore exports would not be cut.

Coup leader Mamady Doumbouya, a former French legionnaire officer, told a meeting of Conde’s ministers and senior government officials that a consultation will be carried out to define the major framework of the transition, then a government of national unity will be put in place to lead the transition.

He said at the end of this transitional phase, we’ll set the tone for a new era for governance and economic development,” he said, flanked by armed soldiers in red berets.

Doumbouya did not say what the transition would entail or give a date for a return to democratic elections. His seizure of power was buoyed by widespread disaffection with Conde, 83, who promised stable democracy but once in power violently silenced opponents, failed to reduce poverty and last year decided to run for a third term in power – a move many said was illegal.

The coup was welcomed by many, but spooked the mining sector. Guinea holds the world’s largest bauxite reserves, an ore used to produce aluminium.

Prices of the metal shot to a 10-year high on Monday, though there was no sign of supply disruptions. In an effort to quell fears, Doumbouya said sea borders would stay open so mining products could be exported.