The Russian central bank said on Friday it is to raise its main interest rate by 0.25 basis points to 8.25 percent in response to growing concerns over inflation. The increase in the refinancing rate, which will be effective from Tuesday, is the second such tightening in the current cycle after the central bank in February raised its rates for the first time in more than two years. The bank said that inflationary pressure in Russia remained \"considerable\" with inflation this year up to April 25 reaching 9.6 percent from the same period the year earlier. \"The decision has been taken due to the continued high level of inflation expectations, higher than predicted inflation forecasts and also taking into account the affect the situation on global markets can have on Russia,\" it said. Russia is emerging from the economic crisis that pushed it into recession two years ago but economists are concerned that persistently high inflation partly linked to a devastating heatwave last year could hamper the recovery.