Venezuela's opposition has called for a fresh strike following clashes between government forces and protesters in the capital, Caracas.
The injured included musician Wuilly Arteaga.
The Venezuelan intelligence service arrested one of the shadow judges, Angel Zerpa Aponte, the opposition-controlled National Assembly said on Twitter.
National Guard troops used tear gas in at least one location in Caracas, blocking protesters with clouds of white gas and rows of officers on motorcycles.
The Mexican government's call adds to growing pressure on Maduro after more than seven million Venezuelans voted in an unofficial referendum at the weekend to repudiate his plans to rewrite the country's constitution and create the new assembly.
With anti-government marchers still clearing the streets on Saturday, Calzadilla said the new strike would take place on Wednesday and Thursday and finish with a march on Friday demanding Maduro scrap his planned Constituent Assembly vote, which is scheduled for July 30.
The president's opponents accuse Mr Maduro of turning Venezuela into a dictatorship and wrecking what should be a prosperous economy.
More than 100 people have died and thousands more been injured in anti-government unrest since April.
Maduro, 54, says the opposition aims to topple his leftist government through the protests, which he says are incited by the United States. The 23-year-old was seen with blood pouring from cuts on the left side of his face. He later tweeted a video from hospital with a bandaged face and clutching his violin. It collaborates with revolutionary Cuba, sending much-needed oil at reduced prices, speaking out against Washington's interference in Latin America and the Caribbean, and welcoming thousands of Cuban volunteer doctors, health workers and teachers who bring medical care and literacy to working people throughout the country.
Venezuela's political crisis has entered a unsafe new stage as the opposition escalates street tactics to try and block a controversial new super-congress Maduro wants to set up with an election next weekend. They want free elections and an end to two decades of socialist rule.
Maduro has accused demonstrators of seeking a coup with U.S. support.
But the government is showing no sign of backing down, announcing that it will put 232,000 soldiers on the streets to ensure the Constituent Assembly goes ahead.
Global pressure has been growing on Maduro to abandon next weekend's vote, including a threat from US President Donald Trump to apply economic sanctions.
"The repression has been brutal and the world has to understand what we are living through in the streets of Venezuela", Machado said.