Those executed included 73 Saudis, seven Yemenis and one Syrian, with some purported to have been members of Al Qaeda and Houthi rebels.
Saudi Arabia on Saturday executed 81 people convicted of crimes ranging from killings to belonging to militant and terrorist groups -- the largest known mass execution carried out in the kingdom in its modern history.
The number of executed surpassed even the toll of a January 1980 mass execution for the 63 militants convicted of seizing the Grand Mosque in Mecca in 1979, the worst-ever militant attack to target the kingdom and Islam's holiest pilgrimage site.
It was unclear why the kingdom chose Saturday for the executions, though they came as much of the world's attention remained focused on Russia's war on Ukraine.
The number of death penalty cases being carried out in Saudi Arabia had dropped during the coronavirus pandemic. However, the kingdom continued to behead convicts under King Salman and his assertive son, Crown Prince Mohammed bin Salman.
The state-run Saudi Press Agency announced Saturday's executions, saying they included those "convicted of various crimes, including the murdering of innocent men, women and children".
The kingdom also said some of those executed were members of al-Qaida, the Islamic State group and also backers of Yemen's Houthi rebels.
A Saudi-led coalition has been battling the Iran-backed Houthis since 2015 in neighbouring Yemen.
Those executed included 73 Saudis, seven Yemenis and one Syrian. The report did not say where the executions took place.
"The accused were provided with the right to an attorney and were guaranteed their full rights under Saudi law during the judicial process, which found them guilty of committing multiple heinous crimes," the Saudi Press Agency said.
"The kingdom will continue to take a strict and unwavering stance against terrorism and extremist ideologies that threaten the stability of the entire world," the report added.
It did not say how the prisoners were executed, though death-row inmates typically are beheaded in Saudi Arabia.
An announcement by Saudi state television described those executed as having "followed the footsteps of Satan" in carrying out their crimes.
Activists fear execution reprisal against Shiite minority
The executions drew immediate international criticism.
"The world should know by now that when Mohammed bin Salman promises reform, bloodshed is bound to follow," said Soraya Bauwens, the deputy director of Reprieve, a London-based advocacy group.
Ali Adubusi, the director of the European Saudi Organisation for Human Rights, alleged that some of those executed had been tortured and faced trials "carried out in secret".
"These executions are the opposite of justice," he said.
The kingdom's last mass execution came in January 2016, when the kingdom executed 47 people, including a prominent opposition Shiite cleric who had rallied demonstrations in the domain.
In 2019, the kingdom beheaded 37 Saudi citizens, predominantly minority Shiites, in a mass execution across the country for alleged terrorism-related crimes.
It also publicly nailed the severed body and head of a convicted extremist to a pole as a warning to others. Such crucifixions after execution, while rare, do occur in the kingdom.
Activists, including Ali al-Ahmed of the US-based Institute for Gulf Affairs and the group Democracy for the Arab World Now said they believe that over three dozen of those executed Saturday were Shiites.
However, the Saudi statement did not identify the faiths of those killed.
Shiites, who live primarily in the kingdom's oil-rich east, have long complained of being second-class citizens. Executions of Shiites in the past have stirred regional unrest.
Saudi Arabia meanwhile remains engaged in diplomatic talks with its Shiite regional rival Iran to try to ease yearslong tensions.
The 1979 seizure of the Grand Mosque remains a crucial moment in the history of the oil-rich kingdom.
A band of ultraconservative Saudi Sunni militants took the Grand Mosque, home to the cube-shaped Kaaba that Muslims pray toward five times a day, demanding the Al Saud royal family abdicate.
A two-week siege that followed ended with an official death toll of 229 killed. The kingdom's rulers soon further embraced Wahhabism, an ultraconservative Islamic doctrine.
'No power' to get rid of death penalty, crown prince claims
Since taking power, Crown Prince Mohammed bin Salman has increasingly liberalised life in the kingdom, opening movie theatres, allowing women to drive and defanging the country's once-feared religious police.
However, US intelligence agencies believe the crown prince also ordered Washington Post columnist Jamal Khashoggi's slaying and dismemberment and overseeing airstrikes in Yemen that killed hundreds of civilians.
In excerpts from an interview with The Atlantic magazine, the crown prince discussed the death penalty, saying a "high percentage" of executions had been halted by paying so-called "blood money" settlements to aggrieved families.
"We got rid of [the death penalty] except for one category, and this one is written in the Quran -- and we cannot do anything about it, even if we wished to do something -- because it is clear teaching in the Quran," the prince said.
"If someone killed someone, another person, the family of that person has the right -- after going to the court -- to apply capital punishment unless they forgive him. Or if someone threatens the life of many people, that means he has to be punished by the death penalty."
"Regardless if I like it or not, I don't have the power to change it," bin Salman said.