UNHCR reported Thursday that between 600,000 and one million Iranian households — up to 3.2 million people — have been internally displaced since the war began on 28 February. The agency called it the fastest and largest wave of internal displacement in the region in decades.
Iran's total population is 88 million. If the upper estimate is correct, 3.6% of the country has been forced from home in a fortnight. When UN Secretary-General Guterres issued the conflict's first consolidated displacement figure on 7 March, the total across Iran, Lebanon, Bahrain, and the wider Gulf stood at 330,000. Iran's figure alone is now roughly ten times that. For scale: Syria's internal displacement took over a year of civil war to reach comparable numbers. This conflict compressed a similar volume into fourteen days.
The displacement has multiple drivers operating simultaneously. Israeli strikes on 30 fuel depots across Tehran and Alborz provinces generated thick toxic smoke that blotted out the sun over the capital and produced the acidic black rain Iranian Red Crescent warned carried sulphur, nitrogen oxides, and hydrocarbon compounds. Tehran Province holds approximately 14 million people. Residents are fleeing both the strikes and their atmospheric aftermath — a displacement pattern that more closely resembles an industrial catastrophe than conventional war. The WHO has warned of ongoing health risks across parts of the capital, but the population is moving faster than any public health response can follow.
Combined with Lebanon's 800,000 displaced, the war has now uprooted more than four million people across the region in two weeks. Iran's humanitarian infrastructure was built over decades to host Afghan and Iraqi refugees flowing into the country — one of the world's largest refugee-hosting populations. It was not designed for millions of its own citizens moving in the opposite direction, internally, under bombardment, with no neighbouring country offering intake.
