Flooding triggered by heavy rains and thunderstorms in the last seven days has affected more than 90,000 people in war-torn Yemen, a UN spokesman said on Friday.

Residential areas, sites for displaced people, farms and water reservoirs have been damaged, said Stephane Dujarric, spokesman for UN Secretary-General Antonio Guterres, citing the UN Office for the Coordination of Humanitarian Affairs (OCHA).

Dujarric said 70 percent of those affected are in northwestern Hajjah Governorate.

Flooding was also reported by OCHA during the same period in central and southern Yemen.

Humanitarian agencies are undertaking more detailed assessments, the spokesman told correspondents at a regular briefing.