More than 96,000 people have been infected with cholera in an outbreak that has caused at least 746 deaths in Yemen since late April, a health official said.
Nasser al-Argaly, health undersecretary in the rebel-run government in Sanaa, blamed the outbreak on the two-year-old Saudi-led campaign against Houthi rebels. The fighting has damaged infrastructure and caused shortages of medicine.
Yemeni medical officials said an aid flight from the United Arab Emirates (UAE) carrying 50 tons of cholera treatments arrived in the southern city of Aden, which is controlled by government forces.
The UAE is part of the Saudi-led coalition.
The UN said earlier this month that 70,000 cholera cases have been reported in 19 of Yemen's 22 governorates.