DUBAI, United Arab Emirates (AP) — Protesters angry over a building collapse in southwestern Iran that killed at least 32 people have shouted down an emissary sent by Supreme Leader Ayatollah Ali Khamenei. A crackdown saw riot police club demonstrators and fire tear gas. Online videos analyzed Monday by The Associated Press showed the Sunday night confrontation. It comes as pressure rises in the Islamic Republic over rising food prices and other economic woes amid the collapse of its nuclear deal with world powers. While the protests so far still appear to be leaderless, even Arab tribes in the region seemed to have joined them on Sunday. This raises the risk of the unrest intensifying.