Officials have linked the blast at the port of Shahid Rajaee to poorly stored chemicals - but the government says it's too soon to determine the exact cause. Local rescue crews are still working to extinguish fires at the harbor, which is one of Iran's most important maritime hubs due to its location on the Strait of Hormuz. Moscow has announced it will send additional fire fighting planes to assist local crews.

Iranian President Masoud Pezeshkian has offered his condolances to the vicitms' families.

Ali Fathollah-Nejad is director of the Center for Middle East and Global Order and joins DW from Hamburg.

00:00 Deadly explosion at Iran's biggest port
02:16 Iranian President Masoud Pezeshkian
03:04 Ali Fathollah-Nejad, Center for Middle East and Global Order