Palestinian President Mahmoud Abbas has clamped down on social media and news websites - the main outlets for debate and dissent in the West Bank - with a vaguely worded decree that critics say allows his government to jail anyone on charges of harming "national unity" or the "social fabric."

Rights activists say the edict, issued without prior public debate last month, is perhaps the most significant step yet by Abbas' government to restrict freedom of expression in areas of the West Bank controlled by the Palestinian Authority. A Palestinian prosecutor denied the decree is being used to stifle dissent and insisted that a new law on electronic crimes was needed to close legal loopholes that in the past allowed offenders, such as hackers, to go unpunished.

However, the government has blocked 30 websites in the past month, according to the Palestinian Center for Development and Media Freedoms, Mada. Most of the sites were affiliated with Abbas's two main rivals -- a former aide-turned-foe, Mohammed Dahlan, and the Islamic militant group Hamas, Mada said. A few of the blocked sites had supported the extremist Islamic State group in Iraq and Syria.

The new decree stipulates prison terms ranging from one year to life for those who use digital means for a range of all-encompassing offenses. The list includes endangering the safety of the state or the public order as well as harming national unity or social peace.

Last week, Palestinian intelligence services in the West Bank arrested five journalists on the basis of the new decree. According to the Palestinian prosecutor’s office, the five are suspected of “leaking information to hostile entities,” although the entities were not specified. The five work for media outlets identified with Hamas, such as the Al-Aqsa and Al-Quds broadcasters, which operate out of Hebron, Bethlehem and Nablus. Separately, four other journalists were called for questioning about social media posts critical of government policy.

The Palestinian rights organization Al-Haq said in a statement on Saturday that it contacted David Kaye, the United Nations special rapporteur on freedom of expression, after the PA approved the decree. Al-Haq said the decree violated international conventions on privacy and rights to freedom of expression.

Al-Haq director Shawan Jabarin told Haaretz the decree was approved by Abbas and published on July 9, without the involvement of rights organizations. In its request to Kaye, Al-Haq said there has recently been a major erosion of freedom of expression in the PA, reflected in the arrest of journalists or their interrogation as suspects. Al-Haq also said that Hamas, which controls the Gaza Strip, has been taking similar steps there against journalists and bloggers.

“The Palestinian split between Fatah and Hamas and between the Strip and the West Bank is very much affecting human rights, including freedom of expression, and recently we have been seeing it intensifying, and we have therefore tried, through this contact, to send a signal to the United Nations and also to the Palestinian leadership,” Jabarin told Haaretz.

Officials at the Palestinian Center for Human Rights said it is monitoring the new policy with great concern, adding that Hamas authorities in the Gaza Strip arrested a reporter from official Palestinian television about a month ago on suspicion of leaking information to Palestinian security officials in Ramallah in the West Bank.

A spokesman for the PA did not respond to the allegations. Over the weekend, an official in the prosecutor’s office in Ramallah told the Associated Press that the law was necessary to combat electronic crimes such as hacking as well as online libel.

“One can criticize [Abbas] and his policy but one cannot accuse the president or anyone else of treason or make fun of him in an image, or something like that,” the prosecutor, Ibrahim Hamodeh, told AP.