A collection of unions called for a two-day strike to mark the killing of protesters at a September 28 rally in the capital.

Government soldiers had opened fire at protesters who had gathered outside a stadium in Conakry in defiance of a ban on the rally.

Election speculation

The demonstration followed speculation that Captain Moussa Dadis Camara, Guinea's president who seized power in a coup last December, would stand in next year's elections.

Rights organisations and the UN say the toll of those killed in the crackdown may have been higher than 150 and that at least 1,200 people were injured.

The military government puts the death toll at 56.

Union officials said the strike also hit the country's mining operations for a second day on Tuesday, halting work at an aluminium refinery and freezing bauxite exports, a major source of Guinea's foreign exchange.

The Guinea Bauxite Company (CBG), a joint venture between Anglo-Australian mining giant Rio Tinto and US Alcoa, said its operations were at a minimum due to the strike.

"They managed to stop CBG activities. We can do no more than assure a minimum service level of the train and the port," a CBG official told the Reuters news agency.

Efforts to resolve the crisis are continuing and last week Mohamed Ibn Chambas, head of the regional grouping Ecowas, met Blaise Compaore, the president of Burkina Fasso, who has been appointed by the body to mediate.