The Central Bank of Russia (CBR) has purchased 200,000 troy ounces (6 tons) of gold in May, boosting bullion reserves to 2,190 tons. Russia increased its gold reserves by 0.3 percent in one month from May 1 to June 1, the central bank reported on Thursday. In May, the regulator held some 2,183 tons of the precious metal. Moscow has been actively beefing up bullion reserves in order to reduce reliance on the US dollar and to diversify its foreign exchange reserves.