This September 2014 video says about itself:
Translated from Dutch NOS TV today:
The problem is that the Saudi authorities have an extremely wide definition of terrorism. Eg, they consider the activists, jailed for advocating the right of women to drive cars and now threatened with beheading, and atheists to be ‘terrorists’.
As this 25 April 2019 video says, these 37 beheaded people were Shia Muslims. Shia Islam is a terrible heresy according to Saudi state religion.
According to the ministry, the verdict is supported by a royal decree.
The ministry’s statement also said that the bodies of two executed men were shown in public. They hung on a pole for a few hours. …
The last time so many people were executed in one day in Saudi Arabia was in 2016. According to human rights organization Human Rights Watch, 47 men were killed on 2 January of that year … It was then the largest mass execution since 1980.