SINGAPORE, Aug 29 (Reuters) - The chief of Singapore's central bank said the city-state is considering new measures that will make it more difficult for retail investors to trade cryptocurrencies at a time when they seem to be "irrationally oblivious" about the risks.

"Adding frictions on retail access to cryptocurrencies is an area we are contemplating," Ravi Menon, managing director of the Monetary Authority of Singapore (MAS) said at a seminar on Monday.

"These may include customer suitability tests and restricting the use of leverage and credit facilities for cryptocurrency trading," he added.

The MAS in January issued guidelines to limit cryptocurrency trading service providers from promoting their services to the public, as part of its attempts to shield retail investors from potential risks.