Muftah bin Hilal bin Abdullah al-Fahmi shot dead Ahmed bin Mohammed bin Kheir al-Fahmi with a pistol after a fist fight, the ministry said in a statement carried by the official news agency SPA.

His beheading brings to 18 the number of executions announced by the Saudi authorities so far this year.

Last year at least 37 people were executed, while 83 were put to death in 2005 and 35 the year before, according to AFP tallies based on official statements.

Executions are usually carried out in public in ultra-conservative Saudi Arabia, which applies a strict form of sharia or Islamic law.

Rape, murder, apostasy, armed robbery and drug trafficking can all carry the death penalty.

The New York-based Human Rights Watch last month asked Saudi Arabia to stay executions after it beheaded four Sri Lankans for armed robbery on February 19 and ordered the public display of their bodies.