The local general court on Saturday had jailed two of them for 15 years, in addition to 2,000 lashes. The other two were sentenced to seven years and 1,000 lashes.
While confirming the verdict, the judge at the Court of Cassation said the offense was serious since the robbers used weapons.
The Riyadh police arrested them after shopkeepers reported that a four-member armed gang had raided their stores, taking money out of the cash registers and their mobile phones.
After carrying out investigations, officers successfully tracked down the men, who were operating in specific areas in the capital.
Meanwhile, police also apprehended a group of five Africans who had cheated members of the public out of SR1.1 million.
Officers said the gang was operating in areas such as Al-Naseem, Al-Manar, Malaz and Sulaimaniah. They were persuading customers in shops to give them money in return for a stake in a lucrative business they claimed to be running.
"Some victims had given SR100,000 each, anticipating a monthly return for their investments," said a police spokesman.
Officers are carrying out further investigations to find out if there were more people involved in the fraud.
Police have issued a warning to the public not to give money to strangers who make such attractive offers, as they are often too good to be true.
