Japan's retail sales tumbled at their fastest pace in more than 4½ years in October as a sales tax hike prompted consumers to cut spending, raising a red flag over the strength of domestic demand.

The government increased the nationwide sales tax from 8 percent to 10 percent on Oct. 1, in a bid to fix the nation's public debt burden, which is the heaviest in the industrial world and more than twice the size of the country's gross domestic product.

However, some analysts have warned that the tax hike, previously postponed twice, could leave the economy without a growth driver amid a slump in exports and production and as other factors drag on the consumer sector.