This time, authorities surrounded a makeshift encampment in Manama, the Bahraini capital, before firing tear gas and ammunition to clear protesters. They acted hours after some demonstrators called for the ouster of Bahrain's prime minister, a member of the ruling family who has served for nearly 40 years, and even an end to the monarchy.
In Libya, after authorities put down a small protest Tuesday, they were confronted with uprisings in three cities Wednesday. And in Iran, skirmishes broke out between critics and supporters of the government, a day after hard-liners called for the execution of two opposition leaders.
Hundreds of Yemenis demanding the resignation of President Ali Abdullah Saleh also took to the streets for a sixth straight day, with protests spreading across three cities. In the southern city of Aden, two protesters were reported killed and eight injured in clashes with security forces, according to local news reports. In retaliation, protesters raided a local government council building and burned four vehicles, witnesses said.
"The fear factor has been broken," declared Mohammed Abu Lahoum, a top ruling party member and influential tribal leader who said Yemen's regime needs to learn a lesson from the uprisings and make compromises to satisfy the people.
Governments have had some success in quelling the recent wave of demonstrators, most notably in Iran, where a heavy-handed response Monday appears to have kept many protesters home, at least for now.
But as populist rebellions spread across the Middle East, many old formulas of suppressing them are faltering, with protesters relentlessly defying their regimes in what amounts to a collective psychological realignment in the region.
Autocrats and monarchs across the Arab world have offered political concessions, including pledges to step down from power, to prevent chaos. But they have only emboldened the streets. They have dispatched armed mobs and security forces to injure, arrest, even kill pro-democracy activists. But the next day, their critics return in even greater numbers, clamoring for action.
"We will not stop protesting until the corrupt regime changes," said Mohammed Ahmed, a union leader in Aden.
The new sense of empowerment has grown dramatically since Egyptian President Hosni Mubarak stepped down Friday. Activists have declared that if Egyptians could overthrow Mubarak, widely seen as the region's most influential and most stubborn autocrat, they could also oust their own unpopular governments. Others drew confidence from the refusal of the armies in Egypt and Tunisia to become tools of government repression, as well as from individual acts of courage.
At the same time, protesters are reassured by the Obama administration's public support for some of the pro-democracy movements. Many said they were re-energized by the U.S. decision not to prop up Mubarak's regime, despite his importance to U.S. strategic interests in the region.
"I am sure the United States will be on our side," said Tawakkol Karman, a well-known Yemeni activist. "The United States now knows it is on the right track by siding with the people, not their current regimes. In this way, the U.S. will regain the influence it has lost in the Arab world."
On Wednesday, the divide between people and their rulers grew in many cities, as protesters stepped up pressure for radical change.
The protests in Bahrain occurred after King Hamad bin Isa al-Khalifa offered condolences and promised reforms and an investigation into the violence. In Libya, protesters called for Moammar Gaddafi, who has ruled since 1969, to step down, despite a long history of the government using heavy force to contain its people. They chanted "No God but Allah, Moammar is the enemy of Allah" and "Down, down to corruption and to the corrupt" before the clashes erupted.
Gaddafi's government, mirroring tactics used by other Arab regimes trying to defuse tensions, offered to double government employee salaries and released from prisons 110 suspected Islamist militants who opposed him. But that emboldened activists to use Facebook and Twitter to call for nationwide protests Thursday.
In Algeria, thousands of protesters called for reforms last week, defying a state of emergency in place for 19 years under which public demonstrations have been banned. On Wednesday, the country's prime minister announced that the state of emergency would be lifted by the end of the month, saying that Algeria could no longer "ignore events taking place in Arab and Islamic countries."
The growing public boldness has stretched beyond calls for democracy and regime change. In the Iraqi city of Kut, protesters hurled stones and set fire to government offices Wednesday to protest poor public services, corruption and unemployment. The actions came despite the Iraqi government's announcement that it would slash electricity costs and use money slated to buy American fighter jets to feed the poor.
Only two years ago, few would have expected the Arab street to defy its leaders. In 2009, opposition demonstrations that erupted in Iran triggered a wave of soul-searching among Egypt's pro-democracy activists, who questioned why their own reform movements were unable to rally people to rise up against Mubarak.
At the time, blogger Nayra El Sheikh said: "I can't help but think: Why not us? What do they have that we don't have? Do they have more guts?"
This time, Egypt's young activists were inspired by a revolution closer to home - Tunisia - which they closely followed on Facebook, Twitter and the al-Jazeera satellite TV channel. The Tunisians set the bar high for defiance. They protested long after their deposed president, Zine el-Abidine Ben Ali, fled the country, demanding that all his allies in the ruling party also step down.
In Egypt, the demonstrations attracted big crowds after pro-Mubarak gangs attacked pro-democracy activists, many fatally, and security forces arrested and detained scores. An emotional speech in Cairo's Tahrir Square by Google executive Wael Ghonim, after he spent 12 days in prison, is credited with inspiring countless ordinary Egyptians to join the protests and ultimately force Mubarak to resign.
Before Mubarak's fall, Yemen's activists staged rallies once or twice a week. After his fall, there have been protests every day, fueled largely by students and human rights activists but increasingly attracting lawyers, union workers and ordinary laborers.
Saleh, who has ruled Yemen for 32 years, announced two weeks ago that he would step down in 2013, when his term expires. But few Yemenis believe him: In 2005, he made the same promise, only to run again a year later. Saleh has also agreed to power-sharing talks with the opposition and said he would not anoint his son as his successor.
But the protesters have also split with the country's political opposition, which seeks reforms rather than regime change. While the protests have been numerically smaller than previous ones, they have become more spontaneous, intense and violent.
"If the regime is pushing peaceful students to use weapons, we can do so, but we are looking to save the country and not destroy it," said Abdul Qader al-Hakami, a protester in the Yemeni capital, Sanaa. "We will be patient like the youths of Egypt and Tunisia, and we hope the regime is wise like Mubarak and Ben Ali to leave office peacefully."
On Thursday, he and other protesters plan to take to the streets again.
Special correspondent Hakim Almasmari contributed to this report.