Gold futures on the COMEX Division of the New York Mercantile Exchange extended the winning streak into a third session on Thursday, as its safe-haven appeal and rising seasonal demand in China buoyed up prices. And a sell-off in U.S. dollar also added to the appeal of gold as an alternative asset.

The most active gold contract for February delivery jumped 8.1 dollars, or 0.5 percent, to 1,647.7 dollars per ounce.

Fresh safe-haven investment demand for gold surfaced on Thursday, after the European Central Bank (ECB) warned of " substantial"downside risks for the euro zone's outlook, traders said.

The ECB left interest rates unchanged at its monthly meeting, but warned of a further weakening of the Eurozone economy. And the ECB president urged EU politicians to reach an agreement on the new fiscal compact by the end of this month, rather than in March as planned.

Meanwhile, the decline in U.S. dollar also offered a strong boost to the precious metal as weaker greenback makes dollar- denominated gold cheaper to holders of other currencies.

Market analysts said that robust demand from India, China also helped keep gold prices firm, as China, the world's second largest buyer of the precious metal, is preparing for the Lunar New Year this month, a key gold-buying period.

Silver for March delivery added 23.4 cents, or 0.8 percent, to 30.124 dollars per ounce.