As the crowd loomed behind police barricades, chants of “Kill the deal!” could be heard for blocks. The event, billed as the “Stop Iran rally” consisted mainly of pro-Israel supporters, though organizers said it represents Americans of all faiths and political convictions, according to The Guardian.

The group is asking Congress to reject the deal under which the U.S. would agree to lift economic sanctions against Iran in return for measures to prevent the country from building nuclear weapons.

As UNIAN reported earlier, six major world powers and Iran reached a nuclear deal in Vienna on July 14.

Under the deal, sanctions imposed by the United States, European Union and United Nations would be lifted in return for Iran agreeing long-term curbs on a nuclear program that the West has suspected was aimed at creating a nuclear bomb.