Syrian President Bashar al-Assad has won a new seven-year term with nearly 90 percent of the vote but Washington said the "non-election" changed nothing and activists said it would spell only more war.
Tens of thousands took to the streets in government-held areas even before the results were announced on Wednesday evening, waving portraits of Assad and the official Syrian flag.
Celebratory gunfire erupted in the capital and in loyalist areas across Syria. At least 10 people were killed as the bullets fell back to earth, according to the Syrian Observatory for Human Rights.
In opposition-held areas where no election was held on Tuesday, activists reacted with the Arab Spring slogan of 2011 that has been the rally cry of their uprising -- "The people want the fall of the regime."
Pro-government newspapers all carried front-page photographs of the re-elected president. Images of Assad in suit and tie, or more rarely military uniform, filled the programming of state television.
The ruling Baath party's newspaper vowed that Syrians would show the same steadfastness against rebel attack in rebuilding their country that they displayed on polling day.
"After the historic vote, Syrians will accomplish a military, political and social mission, as well as the reconstruction of the country, by defying the mortars that are launched every day by the terrorists," Al-Baath said in an editorial.
Some 11.6 million of the 15.8 million eligible voters turned out in government-held areas, according to official figures, despite attacks that killed 24 people on polling day, according to the Observatory.
Critics charged that many of those who voted did so more out of fear than commitment to Assad, whose family has ruled Syria with a rod of iron for four decades.
British Foreign Secretary of State William Hague described the election as an "insult." "Assad lacked legitimacy before this election, and he lacks it afterwards."
US Secretary of State John Kerry called the election a "great big zero."
"With respect to the elections that took place, the so-called elections, the elections are non-elections," Kerry said on a lighting visit to neighbouring Lebanon on Wednesday.
He said "nothing has changed" as a result of the poll and urged Assad's foreign backers to take action to bring an end to the three-year conflict that has left more than 162,000 people dead.
"I particularly call on those nations directly supporting the Assad regime ... I call on them -- Iran, Russia, and I call on Hezbollah, based right here in Lebanon -- to engage in the legitimate effort to bring this war to an end," he said.
Russia earlier called for the speedy appointment of a new UN envoy to resume peace efforts after Lakhdar Brahimi, who brokered two rounds of abortive talks between the government and the opposition earlier this year, stepped down over the weekend saying his mediation had reached a stalemate.
Brahimi had infuriated Damascus by criticising Tuesday's election as an obstacle to his peace efforts.
But Moscow has in turn angered the West by vetoing four draft UN Security Council resolutions in defence of its Damascus ally.
Opposition activists acknowledged wearily that the election was likely to prolong the conflict that has devastated their country and driven nearly half the population from their homes and sparked an exodus of nearly three million refugees abroad.
Speaking to AFP from Turkey, an activist who spent nearly two years trapped under army siege in Syria's third city Homs said he believed in a peaceful solution, but that Assad's win made the prospects remoter than ever.
"Sadly the election means that the fighting and bloodshed will also continue, and no one knows for how long, while the refugees will stay in the camps," said the activist who identified himself only as Thaer.
"The truth is that, even though everyone wants a political solution, that cannot happen with Assad in power... The war will continue, and the Syrians will continue to kill each other."