Iran warned Saturday that coronavirus infections were rising in the southwest despite falls in other regions, as it announced more than 1,500 new confirmed cases.

"All provinces are showing a gradual drop in new infections... except for Khuzestan, where the situation is still concerning," health ministry spokesman Kianoush Jahanpour said in televised remarks.

The health ministry stopped publishing provincial figures for the coronavirus last month. It has instead opted for a colour-coded system of white for low-risk parts of the country, yellow for medium-risk and red for high-risk areas.

Latest reports have shown  Khuzestan red along with a few other provinces, including the capital Tehran and the Shiite clerical centre of Qom, where Iran reported its first cases in February. Early last week, Iran's official daily caseload hit its lowest level since March 10, but it has since climbed again steadily.

Jahanpour said 1,529 new cases were confirmed in the past 24 hours, taking the overall total to 106,220. There were 48 new deaths taking the overall toll to 6,589. Of all those admitted to hospital, 85,064 people had recovered and been discharged.

Experts both at home and abroad have cast doubt on Iran's official figures, saying the actual number of cases could be much higher.