ADEN, Yemen: At least 18 people have been killed in southern Yemen in flooding caused by heavy rains, the government-run news agency Saba reported on Wednesday.

Monsoon rains on Tuesday night flooded the al-Maqatra Wadi in Lahij province, south-west of the city of Taiz, sweeping away dozens of cars and vehicles, local officials were cited as saying.

"The bodies of 10 people have been found and a search is continuing for the other eight," the agency quoted one official as saying, appealing for international help.

Aid organisations have warned that the rainy season could exacerbate a cholera epidemic in Yemen. Since it began four months ago, it has infected more than half a million people and killed nearly 2,000, the World Health Organization said earlier this month.

The cholera outbreak has compounded a major humanitarian crisis in Yemen, where a Saudi Arabia-led coalition intervened in a civil war in 2015, backing government forces fighting Iran-allied Houthi rebels. The fighting has killed more than 10,000 people and displaced another two million.