Those put to the sword have included five Pakistanis, an Indian, two Jordanians, two Syrians and a Yemeni, with few foreign governments willing to publicly appeal for clemency from the wealthy Gulf state.
Three beheadings in a single day on Tuesday -- one for rape and two for murder -- took the total so far this year to 38, according to an AFP tally.
That is about three times the number over the same period in 2014, but observers disagree about the reasons.
"It began before Salman," a diplomatic source said.
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"The Saudi authorities want to show everyone they are strong, people can rely on them to keep the security and the safety in the kingdom," said the source, who did not want to be further identified.
The aim is to deter all forms of violence but the policy is linked to the kingdom's fight against the Islamic State group, the source said.
Security officers arrested three Saudis who allegedly acted "in support of" IS when they shot and wounded a Dane in November. Authorities also blamed IS-linked suspects for the killing of seven members of the minority Shiite community.
In January three Saudi border guards died in a clash with Saudi "terrorists" trying to sneak in from Iraq.
"They certainly don't want to seem soft," Toby Matthiesen, a research fellow in Islamic and Middle Eastern studies at the University of Cambridge, said of the Saudi authorities.