A UN agency has issued a warning for the rare tropical cyclone 'Sagar' in the Gulf of Aden, saying it threatens flash flooding, as authorities say it has struck Yemen's southern coastline.

The Health Ministry's emergency center says that an elderly woman has died after her house caught on fire Friday because of the storm, and that her family failed to rescue her in Khor Maskar in Aden. Another building was evacuated after a balcony collapsed.

The center says that flash flooding has caused sewage to pour onto the streets of the city that has suffered severe infrastructure deterioration since the country's civil war began in 2015.

The Food and Agriculture Organization of the United Nations says the heavy rains could cause favorable breeding conditions for desert locusts.