Saudi-backed government calls for urgent global assistance to help Yemen's war-ravaged health sector deal with coronavirus.

Yemen's Saudi-backed government accused its Huthi foes of covering up a big outbreak of coronavirus in areas they hold and the United Nations warned that the country could suffer a "catastrophic" food security situation due to the pandemic.

The Aden-based government also called for urgent global assistance to help Yemen's war-ravaged health sector deal with the coronavirus.

The World Health Organisation (WHO) says the virus is spreading undetected in the country, divided between the government in the south and the Iran-aligned Huthi group based in the north.

The conflict between the Saudi-led coalition and the Huthis has already caused what the United Nations describes as the world's largest humanitarian crisis, with about 80% of Yemen's population reliant on aid and millions facing hunger.

The government's coronavirus committee reported two more COVID-19 cases in Shabwa province on Monday, taking total confirmed infections since April 10 to 130 with 20 deaths in nine of Yemen's 21 provinces.

The Huthis, who hold most large population centres, have only announced four cases with one death, all in the capital Sanaa.

"Reports on the ground indicate a large number of coronavirus cases in areas under the Huthis' control and hiding this information is completely unacceptable," Minister of Local Administration Abdul Raqib Fath said on Sunday.

He urged the WHO and the international community to pressure the Huthis about declaring cases.

The Huthi movement, which ousted the internationally recognised government from Sanaa in late 2014, denies the charges. On Saturday, its health minister announced two more infections and said the ministry was following all suspected cases, without providing a number.

The WHO says it has been advising local authorities throughout Yemen, where testing capacity is limited, to report cases in order to secure resources, but that the decision to do so rests with a country's leaders.

Sources had told Reuters that both sides have not fully disclosed the extent of the pandemic in a country already plagued by other diseases.

The Aden-based government's health minister said Yemen urgently needed financial assistance and protective gear for health workers in addition to ventilators and test equipment.

Yemen has been mired in violence since the Western-backed coalition intervened in March 2015 against the Huthis, who say they are fighting a corrupt system.

The United Nations' Food and Agriculture Organisation (FAO) said hunger could spread drastically due to the pandemic.

"That situation could be really catastrophic if all the elements of worst case scenarios come to be but let's hope not and the UN are working on avoiding that," senior FAO regional official Abdessalam Ould Ahmed told Reuters.