One-way flights from Russia are selling out or skyrocketing in price.

Some Russians on Wednesday rushed to buy one-way plane tickets out of the country or expressed interest on social media in moving after President Vladimir V. Putin ordered up reservists to bolster Russia’s military in Ukraine.

Tickets to visa-free destinations such as Istanbul; Dubai; Yerevan, Armenia; and Almaty, Kazakhstan, were either sold out for the next several days or their prices had skyrocketed.

There were no one-way tickets out of Moscow to Yerevan, Istanbul or Dubai for Wednesday on an airline ticket aggregator that is popular in Russia. Aeroflot, Russia’s national airline, had no tickets to Istanbul or Yerevan for this week, according to its website. Aeroflot operates up to eight flights per day to the two cities, according to its schedule.

Channels discussing relocations on the Telegram messaging app have been filled with messages about the border situation and possible ways to get out of the country. Some posters said that they were afraid the Kremlin could shut the border soon for men of military age.

Meduza, a Russian media outlet in exile, published a guide to countries Russians can travel to without visas.

Dmitri S. Peskov, the Kremlin’s spokesman, said he would not comment on whether the borders would be shut for potential recruits, asking that people wait for the law to be clarified, according to Interfax, a Russian news agency.

For months since the start of the war, Mr. Putin has avoided mandatory conscription, even a limited one, in order to preserve the sense of normalcy in Russia. However, recent Russian setbacks in Ukraine’s northeast have prompted increasingly vocal pro-war nationalists to demand the Kremlin bolster its efforts.

Some Russians also expressed anger at countries in the European Union for seeking to ban them, even those trying to escape from Mr. Putin’s war machine.

Estonia, Latvia and Lithuania, which all border Russia, this month banned Russians from crossing into their countries by land, sealing one of the last relatively easy routes out of Russia. Latvia said Wednesday it would not issue humanitarian or other visas to Russian citizens seeking to avoid mobilization.

“So, traveling around Europe is a privilege, but fighting Ukraine is a duty,” said Ilya Krasilshchik, a Russian media entrepreneur.

“It’s great that Russian men now will not be able to enter Latvia and Estonia,” he said on Twitter. “But will go to fight against them.”

Finland, the only E.U. country with a land border with Russia that still allows Russians to cross, said that the situation at the border remained normal. The country recently cut the number of tourist visas it issues to Russians by 90 percent, to only 100 a day.

Valerie Hopkins contributed reporting.