Russian authorities have reported multiple cyber attacks on its voting systems as Russians vote in its parliamentary election.
Voting in Russia's parliamentary election runs from September 18 to 20.
The Kremlin is likely to cite the election result as evidence of public support for Mr Putin's policies, in particular the invasion of Ukraine.
Russian authorities have reported multiple attacks on voting systems and communication lines across the country, as Russians head to the polls in a three-day parliamentary election.
The online voting system in Moscow was subjected to a strong attack overnight, but the situation remains under control, the Interfax news agency cited the Central Election Commission's head as saying on Saturday.
The attacks were continuing, but all were being successfully repelled, Ella Pamfilova said, according to state media.
Separately, Russia's digital ministry said it had registered a sabotage attempt on communication lines in the country's Far East, but that the attack had been thwarted and all communication had been restored, state media reported.
President Vladimir Putin earlier accused Ukraine of trying to interfere with the vote, without providing evidence.
Russia's parliamentary election has preceded a diplomatic dispute with Moldova over plans to open polling stations for Russian nationals in the separatist Transnistria region.
Moscow says 220,000 residents of pro-Russian Transnistria, a sliver of land which broke away from Moldova in 1990 at the end of Soviet rule, hold Russian passports and are entitled to vote on Sunday in the election for the State Duma.
Moldova's pro-Western government, which wants to join the European Union by 2030 and denounces the Kremlin's war in Ukraine, says Russians may vote only in a single polling station in the Russian embassy in the capital Chisinau.
It contests the 220,000 figure and opposes any polling station in Transnistria, where it has no control over procedures.
Moldovan authorities this week denounced the Kremlin's 15 planned polling stations as "unacceptable and hostile" and summoned Russian ambassador Oleg Ozerov to the foreign ministry.
Russian Foreign Ministry spokesperson Maria Zakharova retorted by urging Moldova to drop its objections and halt actions that "run against democracy, international law and common sense".
Moldovan Foreign Minister Mihail Popsoi told Moscow "not to interfere with Moldova's plans for peaceful reintegration" of the breakaway territory.
In Russia's last parliamentary election in 2021, authorities in Moscow opened 27 polling stations in the region and more than 59,000 voters cast ballots — with 76.2 per cent backing the United Russia party which supports Russian President Vladimir Putin.
Transnistria is not internationally recognised — not even by Moscow — though a Russian military contingent of some 1,500 troops, which Russia sometimes describes as peacekeepers, remains stationed there despite demands from Moldova for them to leave.
Most anti-war candidates have been barred from participating.
The second day of voting came amid news the US is considering making deals with Moscow before the Ukraine war is over.
The New York Times reported this week, citing two people close to the peace talks, that the White House is now considering signing business deals with Russia before it stops fighting in Ukraine.
"I don't know anything about such signals, and it would be strange to receive them, because we still hear exactly the opposite stance, namely, 'Let's agree on Ukraine and move forward, and everything else later,'" Deputy Foreign Minister Sergei Ryabkov told the RIA state news agency on Saturday.
"Everything else, as they say, will be attached. This also applies to economic aspects, economic projects, too."
Also on Saturday, Poland said it conducted a preventative military air operation during Russian strikes on Ukraine — though concluded their was no violation of Polish airspace.
Russian forces struck an Ukrainian cargo ship and a tanker located in the Black Sea and in one of Ukraine's ports, the Interfax news agency reported on Saturday, citing the Russian Defence Ministry.