SANAA, Yemen — For much of the past year, Yemen's capital has felt like a city on the verge of exploding: dueling Friday protests between supporters and opponents of President Ali Abdullah Saleh, defections by military units and then pitched battles last year between loyalists and those defectors that swept across this ancient city.

But on Tuesday, as Yemenis flocked to the polls for the nation's first vote since the anti-Saleh protests broke out a year ago, those tensions seemed to fade, replaced at least for a day by an infectious optimism and a seeming determination to move past the uncertainty of the past year.

Many acknowledged that the voting was inherently undemocratic: Only one person was on the ballot to replace Saleh, Abed Rabbo Mansour Hadi, Saleh's vice president for the past two decades, who'll serve at the head of a unity government for two years.

The misgivings about the process, however, did little to dampen enthusiasm for the event.

Across Sanaa, polling places were busy for much of the day, and the political divisions seemed to have disappeared. Die-hard supporters of the outgoing president cast ballots at voting centers supervised by opposition activists, coming together to participate in a flawed election that many Yemenis see as a necessary step to prevent the nation from slipping into civil war.

In the capital's Hasaba district, voters cast ballots in the Ministry of Industry and Trade, a government building that armed supporters of Sheikh Sadiq al Ahmar, arguably Yemen's most powerful tribal leader, temporarily seized during fierce fighting last spring with government forces. Within earshot of the sheikh's heavily fortified, partially bombed-out compound, voters emphasized their hopes that the election would signify a new start.

"We consider these elections a way of breaking with the past," said Khaled Saleh al Basha, whose businesses in the district were heavily damaged in the past year's clashes. "God willing, Hadi will rule by bringing us together, instead of using the divisive methods of the previous regime."

Outside the capital, many Yemenis echoed the sense of optimism. Election officials described higher-thanexpected turnout in much of the country, saying that so many voters came out in some rural areas officials had to scramble to deliver ballots.

"People are voting and the area is peaceful," said Sheikh Abdullah al Jumaili, a tribal leader in the impoverished — and often fractious — rural district of al Jawf. "Today marks the dawning of the new Yemen."

Not everyone celebrated, of course. In Change Square, the sprawling anti-government encampment in central Sanaa that's been the heart of anti-Saleh sentiment, most bore black thumbs, showing they'd voted. But some activists protested the vote by dying their thumbs red, a gesture to the hundreds who died in brutal government crackdowns on the protests.

While much of the nation remained calm, a string of violent incidents in the formerly independent south clouded upbeat prognostications for Yemen's future.

Gunmen allegedly linked to the Southern Movement, a loose, officially nonviolent group of secessionists that had called for a boycott of the election, clashed with the security forces that protected polling places in the southern cities of Aden and Mukalla, leaving at least five dead.