Nawaf al-Mutairi was executed in the western city of Medina for the machine-gun killing of fellow Saudi Adel al-Harbi in a dispute, a statement published by the official SPA news agency said.
Another Saudi, Naji Al-Mutleq, was beheaded in the southwestern city of Najran for shooting dead fellow tribesman Abdelhadi al-Mutleq, also with a machine gun, SPA reported.
In neighbouring Jazan, authorities executed Musa Dhafiri for stabbing to death Yehia Hamdi following a disagreement, the news agency added.
Human Rights Watch expressed alarm this month at the surge in the number of executions. Some 19 people were beheaded between August 4 and 20.
Rape, murder, apostasy, armed robbery and drug trafficking are all punishable by death under Saudi Arabia's strict version of Islamic sharia law.
