Silver prices sky-rocketed across the board today on frantic buying by stockists and speculators in line with international trend, recording gains between Rs 565 and Rs 250 per kilo.

The prices touched an all time high level of Rs 12,470 per kilo in Chennai.

Demand for the white metal emerged after it crossed a 16-and-half year record of $8 an ounce in London, as investors sought an alternative to gold and base metals amid threats of terrorism, a declining dollar and increasing industrial demand.

Silver, which had lagged gains in gold, copper and platinum, has caught up by surging 83 per cent in the past year. It's the metal's biggest rally since 1980, when hoarding by billionaire brothers Nelson Bunker Hunt and William Herbert Hunt of Dallas sent the metal to $50 an ounce from $6.

Since the Madrid train bombings on March 11, silver rose by 13 per cent, twice as fast as gold. Demand for the metal is also rising in the electronics  industry, where it is favoured as a conductor, and among jewellery buyers in Asia, who are switching from more-costly platinum.

Both the precious metals, silver and gold, were also higher on Friday in the foreign markets ahead of the release of US employment figures, which may show that the US added more jobs in March than in the previous month.

Weakening US dollar against leading currencies like the euro and the Japanese yen was another boosting factor. Falling American currency makes the dollar-priced precious metals cheaper when bought in other currencies and encourage buying.

The upsurge was led-by a spurt of Rs 565 at Rs 12,470 per kilo in Chennai followed by Mumbai, a rise of Rs 430 at Rs 12,270 per kilo. In Delhi, it gained Rs 375 at Rs 12,220 and in Kolkata by Rs 250 at Rs 12,000 per kilo, respectively.

With the firm general trend, gold also staged a sharp recovery to touch its 14-year high record level last experienced on January 6, this year.