European policymakers struggled to contain the severe market turbulence that has hit the continent and triggered share sell-offs around the world.

The Swiss National Bank made a surprise attempt to halt the rise in value of the franc on Wednesday, saying it was “massively overvalued”, but the impact of the move became more limited as the day wore on. The Italian and Spanish prime ministers also made an effort to stem the rapid rise in borrowing costs that has sucked them into the heart of the eurozone debt crisis.

José Manuel Barroso, the head of the European Commission, underlined the anxiety in the eurozone: “The tensions in bond markets reflect a growing concern among investors about the systemic capacity of the euro area to respond to the evolving crisis.”