The UN’s World Health Organization (WHO) expressed concern about the lack of information on coronavirus cases in Syria and Yemen on Wednesday in an interview with US broadcaster CNN.

WHO is concerned "because the countries who might not be having cases are those with weak health and weak surveillance system(s)," said Abdinasir Abubakar, head of the Infectious Hazard Management Programme at WHO's Regional Office, adding that due to the current situation there might be an "explosion of cases."

Syria, Libya and Yemen are the only three Arab countries that have not yet reported any confirmed cases, CNN noted.

Meanwhile, UN Special Envoy for Yemen Martin Griffiths, on Thursday, called on parties to the conflict to focus on preventing the spread of the disease among Yemeni civilians rather than fight each other.

Since the military escalation began in January, the UN envoy has consistently and repeatedly called for restraint in public and private meetings, according to a statement from his office, which noted that Griffiths has engaged the warring parties in discussions to adopt a nationwide de-escalation mechanism, while working on economic and humanitarian measures to alleviate mass suffering.

"The decision to continue the war is the decision of the parties. Peace is only possible if and when the parties make the responsible decision to put Yemenis first and lay down the arms," he said in the statement.