Venezuela opposition leader Maria Corina Machado was detained at a march in Caracas on Thursday in her first public appearance in months and her ally, former presidential candidate Edmundo Gonzalez, demanded she be freed immediately.

Venezuela’s opposition said its banned leader María Corina Machado was detained after she emerged from hiding to join thousands of Venezuelans protesting against Nicolás Maduro’s planned inauguration after what they say is a fraudulent reelection.

Edmundo González has become a beacon of hope for millions of Venezuelans. They want to call him president. He believes he won that office at the ballot box last year.