"The humanitarian and health situation in Yemen continues to deteriorate," Ahmed Shadoul, the representative of WHO in Yemen, said.
The deterioration of the situation comes as Saudi Arabia has been pounding different areas across Yemen since March 26. Aden was targeted over 100 times by Saudi jets on Tuesday.
"The health situation is especially critical in Aden, with many people no longer having direct access to food, fuel, medical care and safe drinking-water," Shadoul added, Press TV reported.
The WHO said in a report on the same day that four out of five people in Yemen rely on some type of assistance, adding that the UN agency has distributed 46.4 metric tonnes of medicines, medical supplies, and water and sanitation supplies in eight districts of Aden.
The report further said that there has been a significant surge in the number of suspected cases of malaria and dengue fever in Aden, adding that the WHO has provided support to a hospital in the province to deal with the diseases.
The Saudi regime launched its deadly attacks against Yemen without a UN mandate in a bid to undermine the Houthi Ansarullah movement and to restore power to the country's fugitive former President Abd Rabbuh Mansur Hadi, a staunch ally of Saudi Arabia.
More than 3,000 people, including 1,500 civilians, have been killed over the past three months in Yemen, according to the United Nations. Some local sources put this number at 4,500.