A newly-imposed Russian automobile law has left Belarusian roads leading to its giant northern neighbour jammed with vehicles for kilometres, the Belapan news agency reported on Wednesday.
Russian customs officials over the weekend stopped allowing vehicles registered in Belarus into Russia, unless the owner declared the car or lorry as a temporary import - a paperwork task often taking hours.
Belarusian and Russian border authorities in the past had permitted vehicles from each side to be driven into the other country, without paperwork and with minimal delay.
The change, affecting all private autos and lorries owned or operated by a Belarusian citizen, has created near-stationary vehicle gridlock at all major highways connecting Belarus to Russia, officials for the Belarusian customs committee said.
Waits of up to a half day are common at the crossing point on the Moscow-Minsk highway, with similar delays on routes to Kaliningrad and Smolensk, eyewitnesses said.
The Russian clamp-down came in apparent retaliation against a Belarusian law obliging operators of most Russian lorries hauling freight across Belarusian territory to pay the equivalent of 200 dollars, in addition to normal duties.
Minsk began demanding the fee shortly after the New Year. Moscow accused Belarus of implementing the charge in retaliation for fuel price increases imposed by Russia in December.
President Aleksander Lukashenko, Belarus' authoritarian leader, in the wake of the natural gas and oil price increases argued Russia would lose in a trade battle with Belarus, due to Belarus' "strategic" location between Russia and energy markets in Europe.
Lukashenko also has threatened the Kremlin with imposition of rental fees on currently cost-free Russian military bases sited on Belarusian territory.
Russia and Belarus until recently were close allies, with plans to unite into a single country, and Belarus enjoying cut-rate prices for Russian energy in exchange for political support of Russia internationally.
Russian President Vladimir Putin abandoned that policy, making the Kremlin's priority maximum income from energy exports, regardless of who the customer is.