For sellers of traditional watches in the US, it's time to watch out for. Their time may not be up, but the Apple Watch has hit them hard, with sales of traditional watches plunging to a seven-year low.

The infant wearable category, which wasn't seen as a threat by many, grew multifold and the Cupertino-based tech company apparently played a vital role in it, since the steep decline in sales of traditional watches is being attributed to the Apple Watch.

According to NPD Group, sales of watches stood at about $375 million in the US in June, 11% less than sales during the same period last year.

The unit sales of traditional watches in the US witnessed a 14% decline, highest since 2008.

Apple's entry into the wearable space threatened many watch makers. One of the inventors of Swatch, Elmar Mock, predicted before the launch of Apple Watch that the smartwatch's debut will shake-up the centuries-old industry, causing an "ice age," Bloomberg reported.

Apple launched its new portfolio of wearables in April. Several models of the Apple Watch were launched to cater to various customers' demands.

The base version of Apple Watch costs $349, while the 18-carat gold variant sells for about $17,000.

According to BizJournals, the average selling price per Apple Watch was $504, while buyers spent $382.83 on the sport version of the Apple Watch.

It is hard to pin down the exact number of Apple Watch units sold since the launch, as the company's CEO Tim Cook refrains from sharing data to guard against rivals.

But according to Bloomberg, Apple might have sold at least 1.9 million watches at an average price of $499.

As it appears, the Apple Watch was preferred to traditional watches costing less than $1,000. According to NPD, which drew its data from nearly 70 brands, sales of watches costing between $100 and $150 dropped 24% in June.

Will Apple continue to grow at the cost of traditional watches in the long run?