Saudi Arabia's minister for media and culture, Abdel Aziz Khoga, has confirmed censorship of Twitter imposed by a series of government bodies, the Saudi Al-Watan Online
Khoga called on Saudi citizens to "raise their awareness" and contribute to the censorship initiative taken up by the ministry. "People have to take care of what they are writing on Twitter," the minister said.
"It is getting harder to observe around three million people subscribing to the social network in the kingdom," Khoga added.
Last month, Saudi intellectuals called on Saudi Crown Prince Salman Bin Abdul Aziz to order the release of Turki Al-Hamad, a liberal Saudi writer, accused of "insulting Islam" on his Twitter account.
"We hope for, demand and expect a quick decision to be made to correct this grave error that has been committed against [Al-Hamad]," a petition signed by almost 500 people said.
According to AFP, the petition described his arrest as "unjust ... condemnable, reprehensible, shameful and unacceptable." Moreover, it called for a "public apology" to Al-Hamad, saying he was targeted by online "incitement" campaigns to arrest and try him.
Hamad was arrested on the orders of Interior Minister Prince Mohammed Bin Nayef Bin Abdel Aziz, who was tipped off by a religious organisation.
The comments Al-Hamad posted had attacked radical Islamists he said were twisting the Prophet Mohammad's "message of love," and what he described as "a neo-Nazism which is on the rise in the Arab world — Islamic extremism".
The postings provoked fierce debate on social networking sites in Saudi Arabia between supporters and detractors.
Online activist Raif Badawi, another Saudi, was arrested last June in Jeddah and accused of apostasy, which carries the death penalty in the Gulf kingdom.
Badawi helped set up a liberal Saudi website that declared a "day of liberalism" on 7 May 2012, calling for protests against the stranglehold of religious officials on public life in the strict Sunni-ruled monarchy.