The ruble slumped to a record low against the US dollar on Friday as investors worried that the West may tighten sanctions against Russia over its role in Ukraine.
The ruble slid to 37.0260 to the dollar, breaking its previous record low set in March when Russia annexed Crimea from Ukraine.
By 0800 GMT the ruble had recovered slightly to 36.91 to the dollar, still weaker than the 36.75 it closed at on Thursday.
The ruble also slid to 48.61 to the euro, from 48.43, but was still stronger than the record low set in March.
The downward trend for the ruble "might continue further if the geopolitical ground remains shaky," analysts at VTB Capital said.
Russian stocks were also trading lower after having tumbled on Thursday. The ruble-denominated MICEX index was off 0.02 percent and the dollar-based RTS index down 0.27 percent.
Tension is rising over Russian support for separatists in fighting in eastern Ukraine.
"Negative headlines coming out of Ukraine are causing negative sentiment again," said analysts at Alfa Bank.
"Despite President Vladimir Putin's request that militants provide a humanitarian corridor, markets remain volatile," they added.
The West, including US President Barack Obama, threatened on Thursday to impose new sanctions on Russia amid increasing signs its troops are fighting directly in Ukraine.
EU foreign ministers are meeting in Milan on Friday, where they could discuss new sanctions, even though those imposed so far have failed to change Russian policy.
While already slowing, the uncertainty generated by Ukraine crisis and Western sanctions have brought the Russian economy to the brink of recession.