Russian central bank chief Elvira Nabiullina said on Thursday it was too early to say the crisis is over in Russia after the economy was hit by Western sanctions and falling oil prices,  

"It's premature to say that all the features of the crisis are over," Nabiullina said at a bank congress in Russia's second city of Saint Petersburg.

"The risks have softened but remain the same ones and we must realise this," she said, cited by the Interfax news agency

Her statement runs contrary to the optimism demonstrated by the Russian authorities who have said numerous times recently that the worst was over.

President Vladimir Putin even said that the use of the term "crisis" was inappropriate.

On the back of a surge in fighting in eastern Ukraine on Wednesday the ruble plunged spectacularly, losing about 3 percent of its value against the dollar and the euro and reaching its lowest level for two months.

The Ukrainian crisis has led to unprecedented Western sanctions on the Russian economy and last year's collapse in oil prices plunged Russia into a monetary crisis at the end of 2014 that has now become a deep recession.

A degree of stabilisation this spring has seen the ruble claw back some value.

But Kiev's announcement on Wednesday that the pro-Russian separatists in the country's east had launched a major offensive against Ukrainian positions and a drop in oil prices saw the currency fall once more.

Nabiullina acknowledged that "outside conditions remain quite unfavourable."

"Yes, of course, oil prices have grown but even when they are stabilised at the current level, they are a third less than the average over the last 5 years."

Prices for goods that Russia traditionally exports are falling, so "it's not a good idea to think that exports will pull up our economy."

Russia is expected to lose between $150 and $170 billion in export revenues per year compared with its usual level, she added.

Russia's economy contracted by 1.9 percent in the first quarter of the year, the first time this has happened since 2009.

While the ruble had bounced back in recent months, consumption and purchasing power were increasingly affected by the financial crisis.