Demonstrators blocked roads, sacked public buildings and overturned vehicles in the Bouira region, southeast of the capital, Algiers, the reports said.
In the western Tiaret region and in Sidi Ammar in the east, hundreds of people blocked highways to protest against higher transport prices caused by the increase in fuel costs.
The protest movements began on Saturday and continued into Sunday, causing security forces to intervene, newspapers said. Dozens of people were questioned.
Riots also broke out in the western Maghnia region near the Moroccan border, as demonstrators built and set fire to roadblocks to protest at deteriorating economic conditions.
Middle of winter
Fuel price is a perennial source of
discontent in the gas-rich nation
Butane gas and fuel oil are the only available sources of energy in Algeria's remote mountain regions and high plateaus.
The government's decision to raise the price of a litre from 170 to 200 dinars (1.7 to 2.0 euros) in the middle of winter goes against a recommendation from the national parliament.
This is the second wave of major protests against the fuel
increase. Last week protesters took to the streets in the southern regions of Jilfa and Kabylie.
In 2001 hostility to the government erupted into bloody unrest in Kabylie, claiming at least 100 lives.