The strikers set up barricades on the streets, overpowered police, torched two police stations and freed prisoners in Duinguiraye, 400 km northeast of Conakry.
Residents in the Bonfi suburb of the capital Conakry said the security forces had killed one civilian and injured another when they opened fire on youths who started stoning a passing convoy they believed to be transporting the president.
"Two people were hit. One of them died, he was hit in the head," one witness said.
Strike threat
One union leader said the nomination of Camara, formerly Conte's minister in charge of presidential affairs, was not enough to call off a nationwide stoppage planned from Monday.
"We asked for a clean prime minister.
Instead of that we get an old man from the old guard who is too close to the current power structure," Louis Mbemba Soumah, secretary-general of the SNECG teachers' union, said.
"For us the strike order is maintained."
Strike leaders, who say Conte is no longer fit to rule after 23 years in power, had given the president until Monday to name a new premier, as he agreed to do in a deal struck two weeks ago to end an 18-day nationwide stoppage.
The SNECG was not one of the two main unions to have called the original strike and has in the past taken a more militant stance than they have.
Other union leaders declined to comment before a meeting on Saturday to discuss Camara's nomination.