BRUSSELS (AP) — Mounting worries that Italy and Spain won’t be able to repay their debts pummeled stocks and the euro Thursday and piled pressure on the 17-nation currency zone to overhaul its crisis strategy.

And despite indications that the European Central Bank has restarted its bond buying program after a four-month hiatus in an attempt to calm markets, the financial pressures on Italy and Spain remained acute.

European Commission President Jose Manuel Barroso admitted as much, urging eurozone leaders to make further changes to their bailout fund — including boosting its size — to ensure it can effectively stem the debt crisis that has rocked the currency union for 21 months.

Barroso’s appeal and the ECB’s apparent turnaround came just two weeks after eurozone leaders reached what they branded a “historic” deal on the currency union’s crisis strategy, including a second massive bailout for Greece and far-reaching new powers for their rescue fund.

However, the accord failed to stem rising panic on financial markets over the ability of the eurozone’s third and fourth largest economies to repay their debts.