Georgia's president called for protests on Monday following a disputed parliamentary election, and the United States and the European Union urged a full investigation into reports of violations in the voting.
The results, with almost all precincts counted, were a blow for pro-Western Georgians who had cast Saturday's election as a choice between a ruling party that has deepened ties with Russia and an opposition aiming to fast-track integration with Europe.
Monitors from the Organisation for Security and Co-operation in Europe (OSCE) said on Sunday they had registered incidents of vote-buying, voter intimidation, and ballot-stuffing that could have affected the outcome, but they stopped short of saying the election was rigged.
President Salome Zourabichvili urged people to take to the streets to protest against the results of the ballot, which the electoral commission said the ruling party had won.
In an address on Sunday, she referred to the result as a "Russian special operation". She did not clarify what she meant by the term.
The ruling Georgian Dream party, of which Zourabichvili is a fierce critic, clinched nearly 54% of the vote, the commission said, as opposition parties contested the outcome and vote monitors reported significant violations.
Georgian media cited Prime Minister Irakli Kobakhidze as saying on Monday that the opposition was attempting to topple the "constitutional order" and that his government remained committed to European integration.
U.S. Secretary of State Antony Blinken said the United States joined calls from observers for a full probe.
"Going forward, we encourage Georgia's political leaders to respect the rule of law, repeal legislation that undermines fundamental freedoms, and address deficiencies in the electoral process together," Blinken said in a statement.
Earlier, the European Union urged Georgia to swiftly and transparently investigate the alleged irregularities in the vote.
"The EU recalls that any legislation that undermines the fundamental rights and freedoms of Georgian citizens and runs counter to the values and principles upon which the EU is founded, must be repealed," the European Commission said in a joint statement with EU foreign policy chief Josep Borrell.
President Zourabichvili, a former Georgian Dream ally who won the 2018 presidential vote as an independent, urged Georgians to protest in the centre of the capital Tbilisi on Monday evening, to show the world "that we do not recognise these elections".
For years, Georgia was one of the most pro-Western countries to emerge from the Soviet Union, with polls showing many Georgians disliking Russia for its support of two breakaway regions of their country.
Russia defeated Georgia in their brief war over the rebel province of South Ossetia in 2008.
The election result poses a challenge to the EU's ambition to expand by bringing in more former Soviet states.
Moldova earlier this month narrowly approved adding a clause to the constitution defining EU accession as a goal. Moldovan officials said Russia meddled in the election, a claim denied by Moscow.
(Reporting by Felix Light, Lucy Papachristou, Sabine Seibold and Costas Pitas; Writing by Lidia Kelly in Melbourne; Editing by Clarence Fernandez and Angus MacSwan)
By Felix Light and Lucy Papachristou