One person has been killed after multiple explosions were heard around the al-Quds Day march in the Iranian capital, where thousands were taking part in annual rallies held in solidarity with Palestinians, as United States-Israeli attacks across the nation continued for a 14th day of war.

A large midday explosion on Friday rocked a Tehran square filled with demonstrators who were there for the annual event, Iranian state television reported.

The cause of the blast in Ferdowsi Square was not immediately known, but it came shortly after Israel had threatened people to clear the area because it planned a strike.

State media outlet Press TV said one woman was killed from shrapnel as a result of a US-Israeli airstrike, without providing any other specifics.