Sheikh al-Nimr and a number of the other prisoners executed had been convicted following trials that raised serious concerns over the nature of the charges and the fairness of the process, UN Secretary-General Ban Ki-moon said in a statement on Saturday.
The Secretary-General had raised the case of Sheikh al-Nimr with the leadership of the Kingdom of Saudi Arabia on a number of occasions.
The UN chief reiterated his strong stance against the death penalty. He pointed to the growing movement in the international community for the abolition of capital punishment and urged Saudi Arabia to commute all death sentences imposed in the Kingdom.
Mr. Ban also called for calm and restraint in reaction to the execution of Sheikh Nimr and urged all regional leaders to work to avoid the exacerbation of sectarian tensions.