Visibility fell to less than one kilometre (barely half a mile) in central and southern cities as the storm cloaked the region in an eerie orange haze, AFP photographers reported.

Basra and Najaf airports both closed for the duration of the storm, which began to dissipate on Tuesday morning.

Health ministry spokesperson Saif al-Badr said Basra was the worst-hit province, accounting for more than 1,000 of the 3,747 hospital admissions attributed to the sandstorm.

Many of those who dared to venture out in Basra wore face masks to protect themselves from the choking dust, an AFP photographer reported.

Sandstorms are a perennial feature of life in central and southern Iraq but the environment ministry has warned the country can expect to suffer a rising number of "dust days" in coming decades due to the impact of global warming.

A heavy sandstorm in 2022 saw one person die and more than 5,000 treated in hospital for breathing difficulties.