The Yemeni government declared Aden an “infested city” on Monday, as the number of coronavirus cases jumped. The announcement came hours after the World Health Organisation briefly suspended staff movement in Houthi controlled Yemen over security concerns. The country’s doctors have been bracing for a rise in cases since the first diagnoses in April but worry that the shattered healthcare system will not be able to handle a mass outbreak. The Aden-based National Coronavirus Committee on Sunday announced 17 more Covid-19 cases, 10 of them in the southern port city of Aden. This raised the total count in areas under the government control to 51, with eight deaths. The committee said Aden had been declared an "infested city" because of the spread of the coronavirus and other diseases after recent flooding. It said movement from Aden to other regions was barred with the exception of the transport of goods. "The administrative and political situation in Aden is also hampering efforts to combat the coronavirus and this should be remedied so relevant entities can carry out their duties," the committee said on its Twitter account. A five-year war has shattered Yemen's health system, pushed millions to the brink of famine and divided the country between the internationally recognised government and the Houthi group that ousted it from power in the capital, Sanaa, in late 2014. The war is also causing concern as rebels in the capital have only admitted two cases with one death from the virus despite doctors indicating that there were more patients. The government has accused the rebels of covering an outbreak in Sanaa. The WHO said there was full-blown transmission of the virus in Yemen, whose population has some of the lowest levels of immunity to disease compared with other countries. Testing capabilities are inadequate. The WHO directive issued on Saturday notified staff in Sanaa, the Red Sea port of Hodeidah, the northern province of Saada and the central province of Ibb that "all movements, meetings or any other activity" for staff in those areas were paused until further notice. The WHO has temporarily paused its movements in northern areas due to "credible threats and perceived risks which could have an impact on staff security", it said, adding that operations have not been suspended. Three sources told Reuters the WHO had taken the measure to press Houthi authorities to report results of tests for Covid-19, the respiratory disease caused by coronavirus. However, on Monday the WHO reiterated that the measures had already been lifted again and that it was over security concerns. On the situation in the country, the organisation said, "We are competing for resources and supplies in the global market – and a country's 'priority status' in terms of who receives what for Covid-19 is directly linked to how many cases are in country and the need – it is the numbers." The UN has "systematically, for weeks now," advised on case declaration and reporting, but the decision to do so rests with local authorities, the WHO added. The war has left 80 per cent of the population, or 24 million, reliant on aid and some 10 million facing hunger. The UN has warned that Yemen may face as many as 16 million cases of coronavirus. The Saudi-led Arab Coalition to support the government has extended a unilateral ceasefire in the country because of the pandemic and Ramadan, but the rebels are yet to lay down arms and fighting has continued. Saudi Arabia and the UN will host a donor conference for Yemen on June 2, state media reported on Sunday. The kingdom, which is one of the leading donors to Yemen since the 2015 military intervention, did not say how much money was expected to be raised from the event. The SPA did not give details of the conference, but the announcement came as aid organisations said that a coronavirus outbreak could have dire consequences after years of civil war in Yemen.