Protesters have taken to the streets of several Guinean towns as unions resume their general strike, calling for President Lansana Conte to resign.
Some question how long the army will back an unpopular president
Gunfire has been heard near army barracks in the capital, Conakry, and soldiers are preventing people from reaching the city centre.
Groups of youths armed with clubs and machetes have been marching through some suburbs of the capital, Conakry.
At least nine people are reported to have been killed in Monday's clashes.
Several others died in violent skirmishes on Saturday.
Late on Monday, President Conte announced he had ordered the army to take "all necessary measures" to restore law and order after three days of violent protests.
The unions called off last month's 18-day strike after Mr Conte promised to hand powers to a prime minister.
But they renewed the strike action call after saying the man named for the post, Eugene Camara, was too close to Mr Conte.
The BBC's Will Ross in Conakry says security forces are stopping people from crossing the 30 November bridge, which leads to the city's administrative centre.
Some 50 people were killed here last month when security forces opened fire.
Aminata Koroma, a resident of the capital's Dixinn suburb, said she had heard gunfire.
"I see from my window a thick black smoke rising above the stadium. They must be burning tyres. I also hear shooting from time to time," she told the AP news agency.
No international flights have landed in Conakry since Saturday and observers say many neighbourhoods remain deserted.
Our reporter says protesters have ransacked a police station in the southern town of Guekedou and demonstrators are also out on the streets of other towns.
Mr Camara has been in government for several years and worked as the minister for presidential affairs.
"We don't recognise this prime minister, and anyway, it is no longer a question of the prime minister," said Ibrahima Fofana, the secretary-general of the Guinea Workers Union.
President Conte is sick and rarely seen in public
"With the strike that will restart tomorrow [Monday], we are asking for the departure, pure and simple, of President Lansana Conte."
Our reporter says the capital was in chaos on Saturday after protesters went on the rampage, ransacking government offices and the homes of government ministers.
The French Foreign Ministry says it is following the situation "extremely closely" and has urged all parties to exercise restraint.
The unions say Mr Conte is too sick to continue running the country and accuse him of personally securing the release of two prominent men accused of corruption.
The president seized power in a 1984 coup but has since won three elections.
Mr Conte is in his seventies, suffers from diabetes and is rarely seen in public.
Guinea is rich in minerals but is seen as one of the world's most corrupt countries and most people live in poverty.
About 60 people were killed in protests during last month's strike, when security forces fired live bullets to prevent demonstrators reaching central Conakry.
Our reporter says some people question how long the military will continue to support the president.
Some fear that violence in Guinea could spread to its neighbours, Liberia, Ivory Coast and Sierra Leone.
Liberia and Sierra Leone are recovering from years of civil war, while rebels control northern Ivory Coast.