Moscow and Beijing kept increasing their spending on weapons last year, according to a report by the Stockholm International Peace Research Institute. Russia became the world's third-largest arms spender, to the tune of some $8 billion, a 9.3 per cent increase over 2010, AP said, citing the document. China boosted its purchases by 6.7 per cent to around $143 billion. Beijing remains the world's second-largest arms investor. The US, the world's leading arms buyer, cut military expenditure by 1.2 per cent to $711 billion. Europe increased its spending to $407 billion.