CONAKRY (Reuters) - A Guinea court has summoned opposition leaders to appear at a hearing on Thursday after nearly two weeks of protests in which at least eight people have died, officials said on Sunday.

Some 13 opposition leaders - including former prime ministers Cellou Dalein Diallo, Sidya Toure and Lansana Kouyate - have been ordered to appear at Thursday's hearing after a February 27 protest march turned violent.

The opposition organized the march to protest against what it said was President Alpha Conde's attempts to rig legislative elections scheduled for May 12.

The march ended in clashes between protesters and police, sparking 10 days of sporadic protests in the mineral-rich West African country, fuelled by ethnic rivalries.

"The opposition leaders are facing a civil procedure," government spokesman Damantang Albert Camara told Reuters.

Camara said the three people who signed the request for the February 27 march - minor opposition figures - were facing criminal charges.

Conde has promised to bring to justice those responsible for the violence, in which hundreds of people have been injured and scores of businesses pillaged.

Former premier Toure confirmed to Reuters that the leaders of the ADP and CPPFT opposition groups had been summoned to the hearing on Thursday.

"This is an illegal procedure for what was an authorized march: it is a manipulation of justice for political ends," he said. "On Thursday, we will go to the hearing accompanied by all our supporters."

Guinea is the world's top supplier of the aluminium ore bauxite and holds rich deposits of iron ore. But political turmoil has unnerved investors.

The May vote is meant to complete a transition to civilian rule after a 2008 military coup, unlocking hundreds of millions of dollars in European aid.

Conde met last week with representatives of the opposition to establish a framework for talks to resolve the electoral dispute. The main opposition leaders did not attend the meeting in protest against the security forces' use of violence to put down demonstrations.

The opposition says lists of new voters favor regions that support Conde, and has demanded the government replace a South African firm which was given a contract to update the electoral register.

The opposition also wants Guineans abroad to be given the right to vote. There are large Guinean diasporas in neighboring countries, where many support the opposition.

The government has offered to allow civil society groups and foreign diplomats to act as independent observers of the electoral process.

Behind Guinea's political feuding there is a deep-rooted rivalry between the Malinke and the Peul, its two largest ethnic groups. The Malinke broadly support Conde, who comes from that ethnic group, while the opposition draws heavily from the Peul.

(Reporting by Saliou Samb; Writing by Daniel Flynn; Editing by Peter Graff)