The Sudanese health ministry has so far reported 1,111 COVID-19 cases including 59 deaths, with Khartoum state hardest hit.
Authorities intially imposed a curfew in Khartoum for three weeks from April 18. With its twin city Omdurman, the capital has a population of more than five million.
"The health emergency committee decided to extend the curfew in Khartoum state starting Saturday and for 10 days," the official SUNA news agency reported late Friday.
Travel between the capital and other Sudanese states will be banned, the news agency added.
Since March, Sudan has imposed a state of emergency, shuttering schools and universities, and almost totally closing its borders.
The country's dilapidated healthcare system is already strained by acute shortages of medicines and medical supplies.
Last Sunday, the government announced that a minister of state in the transport and infrastructure ministry, Hashim Ibn Auf, had tested positive for the novel coronavirus.