Moldova's pro-Brussels President Maia Sandu on Monday said her camp "won justly in an unjust struggle" in an EU referendum and first-round presidential elections marked by claims of Russian interference.
The referendum on joining the EU passed with a razor-thin majority in the key electoral test for the former Soviet republic bordering war-torn Ukraine.
Sandu said late Sunday that Moldova had witnessed "an unprecedented assault" on its democracy," blaming "criminal groups, working together with foreign forces hostile to our national interests".
The Kremlin, in turn, called on Sandu to "prove" election interference in the country of 2.6 million people and alleged "anomalies" in Moldova's vote count.
Sandu, 52, a former World Bank economist and Moldova's first woman president, managed to top the first round of presidential elections held at the same time as the referendum on Sunday.
But she will face a tough second round on November 3 against Alexandr Stoianoglo, a former prosecutor backed by the pro-Russian Socialists.
- 'Difficult fight' -
"We have won the first battle in a difficult fight that will determine the future of our country," Sandu told reporters, calling on Moldovans to vote in the second round.
"We heard you: we know we must do more to fight corruption," she added.
Sandu, who beat a Moscow-backed incumbent in 2020, applied for her country of 2.6 million people to join the European Union following Russia's invasion of Ukraine in 2022.
With more than 99 percent of the votes counted, the "yes" vote was slightly ahead at 50.46 percent.
The European Union on Monday said voting was marred by Russia's "unprecedented interference and intimidation".
Polish Prime Minister Donald Tusk hailed Moldova as a "brave nation", while European Parliament president Roberta Metsola congratulated the country for its "bravery".
In the presidential election, Sandu gained more than 42 percent of the vote, while Stoianoglo picked up a higher-than-expected 26 percent.
"We have a huge chance to win on November 3 and we will win," he told journalists at his party's headquarters, calling the vote result a "resounding and shameful failure" for the government.
- 'Profound divisions -
Sunday's twin votes revealed "profound divisions", according to Crisis Group's senior EU analyst Marta Mucznik, who added that the impact of pro-Russian disinformation campaigns was "evident".
"Both Brussels and Chisinau must brace for rising tensions and reconsider their strategies if they are to effectively promote the prospect of EU membership," she said.
Sandu's critics say she has not done enough to fight inflation in one of Europe's poorest countries or to reform the judiciary.
In his campaign, Stoianoglo -- who was fired as prosecutor by Sandu -- called for the "restoration of justice" and vowed to wage a "balanced foreign policy".
The 57-year-old abstained from voting in the referendum.
Fears of Russian interference have loomed large.
Police made hundreds of arrests in recent weeks after discovering an "unprecedented" vote-buying scheme that they say could taint up to a quarter of the ballots cast.
Police said millions of dollars from Russia aiming to corrupt voters were funnelled into the country.
In addition to the suspected vote buying, hundreds of young people were found to have been trained in Russia and the Balkans to create "mass disorder" in Moldova, including by using tactics to provoke law enforcement, according to police.
Voter Eugeniu Panfi, a labourer, told AFP in Chisinau on Monday that Moldova "passed this (electoral) test... with difficulty but with gusto," adding the "the hybrid war" with Russia continued.
By Ani Sandu With Julia Zappei In Vienna