The currency market in Moscow was thin as the US markets were closed for Columbus Day.

At 0732 GMT, the rouble was 0.5 percent weaker against the dollar at 66.90, having earlier hit 67.11, the level last seen on Sept. 19.

Against the euro, the rouble shed 0.3 percent to trade at 76.90.

Prices for oil, Russia's key export, fell. Brent crude futures dropped 1 percent to $83.28 per barrel after Washington said it may grant waivers to sanctions against Iran's oil exports next month.

The rouble along with other emerging market currencies also took a hit from the dollar rally after China allowed its yuan currency to weaken.

The situation on Russia's government bond market also raised concerns after the Russian finance ministry had to again cancel an auction of its OFZ treasury bonds last week due to adverse market conditions.

"If international outflow from OFZs continues, it would add to the upward pressure in the dollar-rouble pair," analysts at VTB Capital said in a note.

The threat of further sanctions hung over the market after the West accused Russia last week of being behind a global hacking campaign, analysts at Rosbank said in a note. Moscow has repeatedly denied any wrongdoing.

Russian stock indexes were in the red. The dollar-denominated RTS index was down 0.31 percent to 1,156.10 points. The rouble-based MOEX Russian index was 0.1 percent weaker at 2,449.5 points.