Abdullah forces fire on crowds ahead of planned 'Day of Rage'

The Saudi Arabian government made good on its pledge to crack down on any hint of dissent yesterday, opening fire on protesters who had gathered to voice their discontent at the country's repressive political system.

Witnesses saw security forces shooting on a group of as many as 800 protesters demanding the release of political prisoners in the eastern city of Qatif. There were also reports that stun grenades had been fired at the group, many of whom were wearing face-masks to hide their identities. The protests dispersed after at least three people were injured. About 200 policemen were present at the march.

The violence came as the Saudi authorities steeled themselves to deal with a mooted "Day of Rage" today, an unprecedented possibility in a country where an absolutist monarchy has long ruled unquestioned. After claims last week from political dissidents that at least 20,000 people could march, senior government figures have repeatedly warned that they will take firm action to dissipate any such gatherings.

While protest groups online and elsewhere have given voice to widespread dissatisfaction partly sparked by the wave of protest that has swept across the region following the revolution in Tunisia, fears of violence appear to have cowed the would-be demonstrators. Last week The Independent reported that some 10,000 security personnel were being drafted in to quell any protests.

Most analysts now predict that the turnout tomorrow will be far lower than the dissidents had initially hoped. "I don't necessarily think much will happen," said former judge Abdelaziz al-Gassem, speaking to Reuters. But, he added, "the important thing is that an idea has happened."

The protests in Qatif yesterday, apparently mostly attended by members of the country's Shia minority, follow a series of such protests in the last three weeks that many Sunni clerics in major cities have attempted to paint as a strictly Shia phenomenon confined to the restive east. Many mobile phones in Riyadh received messages this week warning that "secret Shia hands want to corrupt the country".

There have also been repeated claims, from the Foreign Minister Prince Saud al-Faisal among others, that the rising calls for change are the handiwork of hostile foreign powers – generally considered a reference to Iran.

With many in the traditionally conservative country still loyal to the monarchy, and few calling for its overthrow, there is no sense that the established order is on the verge of collapse. King Abdullah was nonetheless sufficiently exercised by the hints of dissent that emerged since the Tunisian protests began to promise $37bn in handouts to improve the lot of students and the unemployed. Protesters say the real issue is their lack of say in the government of a country where political parties remain banned.

While the protests across the region have already led to profound change in Egypt and Tunisia, and may well do so elsewhere, the consequences of serious unrest in Saudi Arabia would be particularly serious for the rest of the world. The country produces a quarter of the world's oil, and prices spiked on the news of yesterday's violence.