MOSCOW - The Russian ruble went into a free fall on Thursday, with its exchange rate against the US dollar reaching a 34-month low.

According to the Moscow Interbank Currency Exchange (MICEX) chart, the exchange rate once slumped to one dollar against 33.55 rubles during the trading session, the lowest level since July 2009.

Market analysts say the ruble's swift depreciation is a result of continuing capital outflow from Russia and risk aversion among investors who consider the ruble a risky asset because its value is directly connected with the volatile global oil prices.

The Russian central bank this week started selling US dollars on the MICEX, the first time since January, to curb the ruble's depreciation. It sold about 70 million dollars on Wednesday alone.

The Russian currency fell to an all-time low of 36.70 against the greenback in February 2009.