Russians waited in snaking queues at the borders of Georgia and Mongolia as they tried to dodge Vladimir Putin's mobilisation order this week.
Images from Maxar Technologies showed thousands of Russian citizens waiting in cargo trucks and cars in gridlock traffic jams meandering behind the frontier lines.
According to the intelligence company - which uses its satellites to track international developments and conflicts - the Georgia queue stretched back more than 10 miles (16km).
The massive traffic jam translated to an estimated two-day wait time on Sunday as more than 3,000 vehicles waited to cross.
An influx of almost 40,000 Russians has already been recorded in Georgia's capital since the start of the invasion in February, according to official documents.
It comes as Kremlin lawmakers weigh up how to manage the mass exodus as they consider closing borders to all military-aged men.
The chaotic scenes have not been seen in the country since World War Two, reports say.
Asked about the prospect of the Kremlin shuttering the border, Kremlin spokesman Dmitry Peskov told reporters: "I don't know anything about this. At the moment, no decisions have been taken on this."
Reports that Russia might close the frontier have contributed to turmoil since President Vladimir Putin gave the order last week to call up hundreds of thousands of reservists in the biggest escalation yet of the seven-month Ukraine war.
Flights out of Russia have sold out and cars have piled up at border checkpoints, including pro-Western Georgia - which allows Russians to enter without a visa.
"Everyone who is of conscription age should be banned from travelling abroad in the current situation," Sergei Tsekov, a senior lawmaker who represents Russian-annexed Crimea in Russia's upper house of parliament, told RIA news agency.
Two exiled news sites - Meduza and Novaya Gazeta Europe - both reported that the authorities were planning to ban men from leaving, citing unidentified officials.
The mobilisation was accompanied by an announcement by Putin that Moscow would stage votes to annex four Ukrainian provinces occupied by its forces.
The West calls the votes, due to conclude on Tuesday, a sham pretext to seize territory captured by force.
Mobilisation has led to the first sustained protests in Russia since the war began, with one monitoring group estimating at least 2,000 people have been arrested so far.
All public criticism of the "special military operation" is banned.
The past few days have also seen the first sustained criticism of the authorities on state-controlled media since the war began, with pro-Kremlin commentators denouncing officials for calling up people too old to fight.
On a talk show on Russia's main state channel, pro-Kremlin commentators demanded harsh punishments for draft officers who call up the wrong people.
"Can we just shoot them?" asked presenter Vladimir Solovyov.
"I am in favour. I would just drag out a couple of those draft officers publicly," he said. "Grab that draft officer by the ear and send him to the front in the Donbas!"
Peskov acknowledged that some call-up notices had been issued in error, saying mistakes were being corrected by regional governors and the ministry of defence.
Russia counts millions of former conscripts as official reservists.
The authorities have not spelled out precisely who is due to be called up - that part of Putin's order is classified - but have said they will draft 300,000 people, mostly with recent military experience.
Britain's Ministry of Defence said on Monday "many tens of thousands" of draftees had already received papers.
They were expected to be sent swiftly to the frontline where they were "likely to suffer a high attrition rate", it said.
"The lack of military trainers, and the haste with which Russia has started the mobilisation, suggests that many of the drafted troops will deploy to the front line with minimal relevant preparation."
Images circulating on the internet have shown clashes between crowds and police, particularly in areas where ethnic minorities predominate, such as mainly Muslim Dagestan in the south and Buryatia, home to Mongol Buddhists, in Siberia.
More than 70 people were detained at protests against mobilisation in Makhachkala, Dagestan's regional capital, local news outlet Kavkaz Realii said.
It said security forces used stun guns, batons and pepper spray against protesters.
