The bus was traveling from Algiers to Tikjda, a mountain resort popular with tourists when it fell 150 meters into a ravine near the town of El Asnam, the source said, according to Chanel TV.
All those injured were transferred to a hospital in nearby Bouira.
The mountainous region of Tikjda is a popular holiday destination for Algerians, who have flocked there in large numbers after the heavy snowfall of recent weeks.
Speeding motorists, including public transport drivers, is the main cause of road accidents in Algeria, according to the national road safety agency.
In 2021, the latest figures available, Algeria recorded almost 7,186 traffic accidents, resulting in 2,643 deaths and 11,479 injuries.
RHM/PR