The pound traded at 34 to the US dollar on Monday, down from about 30 last week, traders said.

Sudan devalued its currency to 18 pounds per US dollar from 6.7 previously earlier this month, hoping to attract investment and crush a ballooning black market.

Hard currency remains scarce in the formal banking system, however, forcing importers to resort to an increasingly expensive black market. "There is a huge shortage in the market and not enough dollars," one trader told Reuters.

Sudan's economy has been struggling since the south seceded in 2011, taking with it three-quarters of its oil output, but the United States lifted 20-year-old sanctions on it in October, pushing it to embark on sweeping reforms.

Street protests have broken out last week after bread prices doubled, following a government decision to eliminate subsidies in its 2018 budget as part of austerity measures.