RIYADH, SAUDI ARABIA - With a growing number of Saudi citizens calling for change, the kingdom is turning to old tactics to keep dissent at bay, banning protests, detaining some activists and blocking Web sites carrying petitions for reform.

The sharpest warnings came over the weekend, ahead of a "day of rage" called for Friday. The Interior Ministry said security services would prevent any attempt at disorder, and a government-backed council led by Saudi Arabia's top Muslim cleric issued a statement backing the protest ban.

But the signs of discontent that have emerged here in recent weeks have been notable for their boldness. Some activists say they hope that the uprisings that have toppled Arab leaders in Egypt and Tunisia and left others in the region imperiled will show ordinary Saudis that their royal family also must be held accountable.

"The idea is to really educate the public that these people are really not untouchable," said Mohammad Fahad Al-Qahtani, head of the Saudi Civil and Political Rights Association. On a recent Monday, Qahtani joined about 30 other democracy activists at home in Riyadh to discuss whether other regimes' collapse could mean that Saudi Arabia might follow.

"Saudi Arabia cannot run away from the ripples and ramifications" of what's happening in the region, said Khalid al-Dakhil, a well-known Saudi political sociologist. "This is not going to be as fateful and dangerous as Tunisia or Egypt or Libya now. But they really have to take this seriously and readjust and make immediate political and constitutional reforms."

People who have met recently with top Saudi officials say they have seemed dismissive of the idea that the democracy activists represent any real challenge to the royal family. In a meeting with activists and intellectuals, Prince Nayef, the interior minister, argued that so long as Saudi leaders keep the country's conservative Islamic religious leaders content, liberal calls for democracy will pose little threat, according to one participant.

Still, activists said the meeting was an indication of concern that the uprisings elsewhere might spread to Saudi Arabia, which has remained stable through decades of turbulence in the Middle East, with virtually all power and privilege still consolidated in the ruling family.

A first attempt to address discontent came last month, in the form of a $36 billion benefits package announced by King Abdullah bin Abdul Aziz, the 87-year-old monarch, as he returned to Riyadh after three months of convalescence abroad. But the calls for change have grown beyond demands for better jobs to include three recent petitions demanding a transition to constitutional monarchy, greater accountability in state spending and elections to a council that advises the king.

Some observers caution that Saudi Arabia is in many ways different from Egypt and Tunisia and that there are several reasons it would be difficult for an uprising to take hold here.

Abdullah is still broadly admired among Saudis, even if some of his deputies are disliked. There is no culture of demonstrations in the large, diffuse desert kingdom, and even some of the top liberal leaders who drafted petitions have not embraced street protests.

Restrictions on women and men mixing limit crowd numbers, and an aggressive domestic intelligence service and a large secret police force will work to thwart any plans for demonstrations. Intertribal conflicts also could keep people from banding together.

The three petitions were signed by students, moderate Islamists and intellectuals during the last week in February. In addition, a young Saudi man, Ahmad al-Wadaani, has posted a video of himself on YouTube demanding an end to the monarchy. And a group of moderate Islamists has announced plans to form a political party, in defiance of a Saudi ban.

Dozens of women clad in black abayas braved security police officers, who beat them, to stage a sit-in outside the Interior Ministry recently. They were demanding that their husbands and brothers be released from prison or at least given fair trials.

Some political observers here say Tunisia and Egypt have provided politically immature Saudis - with no parliament, unions or history of political participation - a model that they lacked when a reform movement tried to take hold in the 1990s. Seeing the demonstrations elsewhere has made Saudis feel as if they have to speak out, too.

"We cannot accept being ruled by a monarchy like in the Middle Ages," said Mohammad al-Hodaif, an American-educated, early pioneer in the Saudi human rights movement who was jailed for four years in the 1990s. "We need a clear transition of power. We want our share in the political decision making."