Supporters are gathering outside a courthouse in Caracas awaiting the first appearance of opposition leader Leopoldo Lopez following his first night in jail.
National Guard troops in armored vehicles stood watch over demonstrators calling for the release of Lopez. The mood is tense in Venezuela following protests that have resulted in at least 4 deaths and more than 100 injuries over the past week.
Authorities accuse Lopez of fomenting violent protests to push for the overthrow of the socialist government of President Nicolas Maduro.
Prosecutors at Wednesday's hearing are expected to announce what charges Lopez will face and whether he will remain in custody. An arrest warrant earlier said he could face charges that include homicide. Lopez made a dramatic surrender to authorities on Tuesday while surrounded by thousands of supporters.