Thick black smoke billowed into the sky, making day seem more like night.

The low-grade oil has been used to fuel power plants amid Iran’s international isolation. Tanks of mazut may now be burning near the city.

Thick, toxic smoke and black, acid rain have blanketed Iran’s capital, Tehran, this week, after missiles damaged oil depots and refineries. Researchers warn that it probably contains chemicals that are harmful to people and the environment. What is black rain, how does it form and how long will it take to disperse?

President Trump told a reporter during a press conference Monday on Iran that the school bombed near Tehran on the first day of the war is still under investigation.

The Strait of Hormuz, a conduit for a fifth of the world’s oil, is all but closed as war in the Middle East expands. A British agency said three ships were hit by unidentified projectiles in or near the strait.

Switzerland is temporarily closing its ‌embassy in Tehran due to the war in the Middle ​East and increasing security ​risks, the foreign office said ⁠on Wednesday.

A poster of Ayatollah Mojtaba Khamenei, the successor to his late father Ayatollah Ali Khamenei as supreme leader is placed on an anti-riot police car as policemen stand on top of the car, during a rally to support him in Tehran, Iran, Monday, March 9, 2026. (AP Photo/Vahid Salemi)