Heavy clouds of dust covered Israel on Thursday afternoon. The air was thick with dust in most areas of the country, particularly in the south and the central district.

Medical professionals warned all those with heart or lung conditions, the elderly, pregnant women and young children to remain indoors with the windows closed until the dust passes. Paramedics reported a significant increase in the number of calls for help since the dust arrived.

The weather caused problems at Ben-Gurion Airport, where the low visibility forced air traffic controllers to reduce landing frequency. Flights were delayed as pilots circled above the dust clouds, waiting for their turn to land.

Several pilots expressed fear that their fuel supplies were too low to allow them to circle for long. They were rerouted to Cyprus.

The Sde Dov airport in Tel Aviv shut down completely and its traffic was rerouted to Ben-Gurion.

Environmental scientists reported low air quality, with 1,428 micrograms of dust to cubic meter of air in Be'er Sheva and more than 1,000 micrograms per cubic meter in Tel Aviv. In comparison, the normal level of air contamination stands at under 100 micrograms per cubic meter.

Meteorologists were optimistic, saying the heavy dust could be a sign of approaching heavy rains. Israel has suffered an unusually dry winter, and water resources are dwindling.