Sudan has announced a three-week curfew starting Saturday in Khartoum state, including the capital and its twin city Omdurman, after reporting its biggest daily jump in confirmed novel coronavirus cases.

The government "declared a full curfew in the state of Khartoum starting Saturday, April 18, and for three weeks" to tackle the virus, information minister and government spokesman Faisal Salih said in a statement Monday.

He said grocery stores and pharmacies would be exempted for limited daily hours, which the government has yet to announce. 

People will still be allowed limited movement within their neighbourhoods to buy supplies, he added. 

The country's health ministry earlier reported 10 new COVID-19 cases, its biggest daily jump so far, bringing total reported infections to 29. 

The death toll stands at four, according to the ministry. 

All cases but one were in Khartoum state, the country's most populous, according to health minister Akram Ali al-Tom. 

"After the latest rise, we have now reached the stage of community spread... which is the beginning of a slide towards a wider outbreak of the disease," he said. 

He also said the country's ailing health system was suffering shortages of medicine and medical supplies.  

Sudan has since last month declared a state of emergency, shuttered schools and universities, and almost totally closed its borders.