Yemen reported nine new coronavirus infections and one new death from the disease on Monday, raising the total number of cases to 21.
Eight cases were detected in the southern port city of Aden and another infection was recorded in Hadhramout region, the country's supreme national emergency committee said on Twitter.
The province was where Yemen recorded its first case of Covid-19 disease on April 10. So far, three people have died.
Yemen is already grappling with the world's biggest humanitarian crisis caused by a war between the Saudi-led coalition seeking to restore the internationally-recognised government and Houthi rebels which drove the government from the capital, Sanaa, in late 2014.
The emergency coronavirus committee belongs to the Yemeni government, whose interim capital is in the southern port city of Aden.
Yemen's Houthis said on Tuesday a Somali national identified as the first case of the novel coronavirus in the capital Sanaa was found dead in a hotel there on Sunday, the group's al-Masirah TV reported.
Authorities carried out tests on the body and showed that he died from the virus, Masirah said, adding that all people that had interacted with him had been isolated.
But the United Nations says it fears the coronavirus could be spreading undetected across the country among an acutely malnourished population with inadequate testing capabilities and protective equipment.
The UN office for the Co-ordination of Humanitarian Affairs said this week that "based on the transmission patterns of the virus in other countries... there is a very real probability that the virus has been circulating undetected within communities".
The Aden-based emergency coronavirus committee has also voiced concern that Houthi officials are not admitting to a coronavirus outbreak in Sanaa.
OCHA estimates Yemen has just 194 ventilators and 530 intensive care beds.
The World Health Organisation has said it fears that Covid-19 will impact Yemen severely as the population has some of the lowest levels of immunity to disease compared with other countries.
Around 80 per cent of the population, or 24 million people, rely on humanitarian aid and 10 million are at risk of starvation in Yemen.