Earlier in the day, Maduro announced his decision to call the constituent assembly to amend constitution. The country's opposition criticized the step, accusing Maduro of staging a coup.
"The assistance was provided so far to 37 people, 30 of them suffered from various injuries, one was wounded by bird shot, three more suffered from asphyxiating gases and the same number of people felt unconscious," Muchacho wrote on Twitter.
According to Muchacho, the majority of victims had already been discharged from hospital, except for one man who received remained in critical condition after receiving a blow on the head.
Venezuela has been experiencing mass protests for a long time, with the most recent unrest flared up in April after country's Supreme Court tried to take over legislative powers from the opposition-controlled National Assembly. The top court reversed the ruling but this did not prevent demonstrations from taking place across the country, which claimed 28 lives.