Switzerland's financial regulator has responded to the booming interest in digital currencies such as bitcoin with a rulebook to support those involved in the market.

The Swiss Financial Market Supervisory Authority (Finma) said it would regulate certain so-called initial coin offerings (ICOs), a fundraising method that has soared in popularity over the last year, to apply anti-money laundering laws to some sales.

Eager to attract more start-ups as other regulators show resistance to cryptocurrencies, Switzerland has already launched a 'Crypto Valley' in the Swiss city of Zug, while economics minister Johann Schneider-Ammann has said he wants the country to be the "crypto-nation".