Russian Prime Minister Dmitry Medvedev on Saturday ordered the central bank to step up currency interventions to halt the losses of the ruble, which this week hit its lowest level for three years. The ruble came under its biggest attack since the 2008-2009 financial crisis as investors fled to safe havens amid the trouble in the eurozone and were also spooked by the falling price of oil. Russia\'s central bank regularly intervenes to keep the ruble within a floating range against the euro and the dollar but Medvedev called for firmer action. \"There can of course be different emotions but there are rules, including on the currency corridor, and the central bank should implement them,\" he told the head of the Russian central bank Sergei Ignatiyev. \"Interventions should be stepped up, naturally keeping an eye on the economic situation, European trends and the oil price,\" he said at the meeting at his Gorky residence, quoted by Russian news agencies. Ignatiyev revealed that on Friday alone the Russian central bank had used $200 million to support the ruble and stop it weakening beyond a certain range. A dramatic loss in the value of the ruble would be a nightmare for the government of President Vladimir Putin, which is hoping economic stability will keep a lid on an unprecedented outburst of opposition protests. Ignatiyev predicted that if the price of oil -- Russia\'s main export -- appreciated then the ruble would strengthen but if crude fell it could weaken further. \"But not at the speed that we have seen (in the last week) as we will use currency interventions much more actively,\" he said. \"In general, the situation is under control.\" Russian news agencies said Medvedev and Ignatiyev agreed in the meeting that the central bank should keep the ruble within its corridor, which is fixed at between 32.15 rubles and 38.15 rubles against a euro/dollar currency basket. The ruble was trading on Friday at 37.27 rubles against the currency basket, meaning that it was testing its upper limit that the central bank must keep the currency beneath. The currency basket that is is ruble\'s measuring stick is made up of 0.45 euros and $0.55. Russia is currently enjoying relatively robust growth and a low budget deficit compared to its debt-laden partners in the eurozone. But investors are extremely worried by the extent of capital flight which amounted to $35 billion in the first quarter alone.