MOSCOW: The Russian rouble crossed the 76 threshold versus the US dollar on Thursday, weakening to its lowest in more than eight weeks as a sudden sell-off on the Wall Street curbed appetite.

At 0730 GMT, the rouble was 0.6% weaker against the dollar at 76.31, its lowest since Dec. 1, 2020.

The US dollar strengthened following a stock market rout, triggered by concerns excessive valuations boosted safe-harbour demand for the US currency, pushing emerging market currencies lower.

Versus the euro, the rouble weakened 0.4% to trade at 92.20.

The threat of new sanctions against Moscow over Kremlin critic Alexei Navalny's arrest, which last week prompted nationwide demonstrations, has plagued the rouble in recent days. More protests are scheduled for Sunday.

Police in Moscow on Wednesday detained the opposition politician's brother, Oleg, and searched the homes of his associates and other properties linked to him.

The rouble would be under pressure from political risk in the run-up to the weekend, but could gain a foothold near 76 to the dollar, Sberbank CIB analysts said in a note.

Brent crude oil, a global benchmark for Russia's main export, was down 0.8% at $55.39 a barrel, pushing Russian stock indexes lower.

The dollar-denominated RTS index was down 1.6% to 1,370.3 points.

The rouble-based MOEX Russian index was 0.8% lower at 3,317.5 points.