Video aired on Iranian state television showed Iranian President Masoud Pezeshkian greeting people at a Quds Day rally in Tehran on Friday. Pezeshkian was seen walking through the streets, meeting demonstrators and posing for photographs. Quds Day, also known as Jerusalem Day, is observed on the last Friday of Ramadan and is held annually to express support for Palestinians. Iran’s Supreme National Security Council secretary Ali Larijani also attended the rally and said U.S. President Donald Trump did not understand that Iran was a “determined nation.” A large explosion was later reported at a square in Tehran where demonstrators had gathered, according to Iranian state television. The cause of the blast was not immediately known and there were no immediate reports of casualties. The Israeli military declined to comment when contacted, and Iranian authorities did not provide further details.