LIFE’s gallery of the election protests in Tehran:

As protests and counter-protests unlike anything seen in Iran since the 1979 Revolution roil the country and captivate the world, LIFE presents photographs taken by an Iranian who is there, in the midst of the action.

EDITOR’S NOTE: The Tehran-based photojournalist who made these pictures is now missing. See next caption for details.

The images, videos and messages from the protests and the Iranian government are gripping.So are the dispatches from citizens and journalist, both domestic and foreign, who are there now. There is a reason our 1st amendment protects freedom of speech, press, religion, assembly and petition.

Update from LIFE Editor:

A NOTE TO OUR READERS: We are saddened to report that the Iranian photojournalist, whose pictures appear in this gallery, is missing. He has not been in contact with us; this morning we received the following email from one of his relatives. We will update this space when we have more details. THE EMAIL: Hi im [photographer’s relative], when he go out side yester day for he never came back home and also his friend and a lot of our young brave people, government arrested them [. . .] don’t let them suffer in those bloody hands. With thanks.