Russian security forces have detained more than 1,300 people protesting against President Vladimir Putin's partial military mobilisation, according to an independent protest monitoring group.
The OVD-Info group said 1,311 people across 38 Russian cities were arrested in the hours following Mr Putin's announcement.
It said those figures included at least 502 in Moscow and 524 in St Petersburg, Russia's second most populous city.
Unsanctioned rallies are illegal under Russia's anti-protest laws.
In a statement quoted by Russian news agencies, Russian Interior Ministry official Irina Volk said officers had cut short attempts to stage what it called small protests.
"In a number of regions, there were attempts to stage unauthorised actions which brought together an extremely small number of participants," Ms Volk was quoted as saying.
"These were all stopped. And those persons who violated laws were detained and taken to police stations for investigation and [to] establish their responsibility."
One-way flights out of Russia were rocketing in price and selling out fast after Mr Putin ordered the immediate call-up of 300,000 reservists.
Russia releases 10 foreigners as well as Azov fighters
Russia released 10 foreign prisoners of war captured in Ukraine following mediation by Saudi Crown Prince Mohammed bin Salman.
The freed prisoners were American, British, Croatian, Moroccan and Swedish nationals, the Saudi foreign ministry said in a statement, adding that a plane carrying the prisoners had landed in the kingdom.
"The relevant Saudi authorities received and transferred them from Russia to the kingdom and are facilitating procedures for their respective countries," the statement said.
The ministry did not identify the prisoners.
British Prime Minister Liz Truss hailed the release of the British nationals on Twitter as "hugely welcome news" after "months of uncertainty and suffering for them and their families".
British MP Robert Jenrick said British man Aiden Aslin was among those released. Mr Aslin was sentenced to death by a court in the self-proclaimed Donetsk People's Republic (DPR), one of Russia's proxies in eastern Ukraine.
The Russian-backed separatist state declared independence from Ukraine in 2014.
It was recognised by Russia as an independent state only days before it invaded Ukraine, and has since received support from Russian forces.
Ukraine officials have claimed the DPR's militia has been under the direct command of the Russian army for several years.
Russia also released US citizens Alexander Drueke, 39, and Andy Huynh, 27, a family representative told Reuters on Wednesday.
The pair, both from Alabama, were captured in June while fighting in eastern Ukraine where they went to support Ukrainian troops resisting Russia's invasion.
Large numbers of foreigners have travelled to Ukraine to fight since Russia's February 24 invasion. Some of them have been caught by Russian forces, along with other foreigners in the country who say they were not fighters.
Reuters could not immediately establish if the released group included Britons Shaun Pinner and Morocco-born Brahim Saadoun, who were also captured and sentenced to death in Donetsk.
A Swedish citizen, captured at the port city of Mariupol and facing a possible death sentence under the laws of the DPR, was among those released, Swedish Foreign Minister Ann Linde said.
"I can confirm that the Swede who in May was taken into custody by Russian forces is free and on his way to Sweden," Ms Linde told Swedish news agency TT on the sidelines of the United Nations General Assembly in New York.
In another swap announced on Wednesday, 200 POWs from Ukraine's Azov Regiment, who were captured during the battle for the port city of Mariupol, were freed in exchange for pro-Russian opposition leader Viktor Medvedchuk.
The head of the UN human rights mission in Ukraine said earlier this month that Russia was not allowing access to prisoners of war, adding that the UN had evidence that some had been subjected to torture and ill-treatment that could amount to war crimes.
Russia denies torture or other forms of mistreatment of POWs.
Reuters/AP/ABC
