Dubai (United Arab Emirates), 13 March (LaPresse/AP) – A powerful explosion has struck the centre of Tehran in a square packed with demonstrators, according to Iranian state television. The explosion struck Ferdowsi Square, not far from Tehran University, the epicentre of ongoing demonstrations for Quds Day, or Jerusalem Day. A video released by the semi-official Tasnim news agency showed a column of grey smoke rising as demonstrators shouted “Death to Israel!” and “Death to America”. The cause of the explosion was not immediately clear. Israel had previously warned of the possibility of an attack in the area. The authorities in Tehran have not provided any details at this time.