CONAKRY, Guinea - At least four people were killed in Guinea's capital on Saturday as protesters rioted against the president's decision to appoint a political ally as prime minister, medical officials said.

President Lansana Conte, who seized power in the West African country in a 1984 coup, agreed last month to share power by appointing a new prime minister, a key demand of union leaders who led a 17-day strike calling for Conte's resignation.

The strike had spiraled into violent street protests, leaving at least 59 dead and bringing the country to an economic standstill.

According to the agreement with union leaders, however, the new prime minister could not be a current member of Conte's government. Conte appointed Eugene Camara, a member of his Cabinet.

Demonstrators threw rocks, ransacked government buildings and set up barricades made of burning tires Saturday to protest the appointment. Ousmane Bah, a doctor at a hospital in the capital, said at least four people had been killed of gunshot wounds.

"Wake up! Get out of your houses! The president has insulted us!" protesters chanted in the capital.

Witnesses said Conte's bodyguards opened fire to try to frighten protesters who were throwing rocks at his car as he attempted to flee Conakry. One witness, Mouctar Diallo, said he saw two people fall to the ground after the shots were fired.

In other parts of the country, angry crowds vandalized government buildings and set a policeman on fire, private radio station FM Liberte reported. His condition was not immediately known.

Ba Mamadou, a spokesman for the opposition and head of a major political party, called on Guineans to "fight to gain our freedom" and force the president to step down.

"We no longer see any choice but violence in the street. Our people need to take to the streets to fight. The time for negotiation is over," he told The Associated Press.

Although Guinea's population of 10 million is impoverished, the country is home to half the world's reserves of bauxite, a material used to produce aluminum.