Major floods across much of Iran have left 19 people dead and more than 90 injured, blocking roads and triggering landslides with warnings of more heavy rain to come, emergency services said Monday.

Such a widespread flood threat is unprecedented in arid Iran, which until 2018 was dealing with decades of drought.

Seventeen people were killed and 94 injured in the southern city of Shiraz, one person died in the western province of Kermanshah and another in Lorestan, also in the west, rescue services said.

The national emergency has struck in the middle of Nowruz, the Iranian New Year holiday, with many relief workers also on vacation.

Many of those killed in Shiraz were holidaymakers caught in the flood as they entered the city in their cars.

With 25 of Iran's 31 provinces experiencing floods or facing imminent threat, the country's National Crisis Management Committee was activated at cabinet level.