More anti-government demonstrations will be held this weekend as fears grow the government could be overthrown in a coup.
Over the last four weeks, violent and deadly clashes have broken out between opposition protesters and the police.
At least 29 people have died, hundreds have been injured and more than a thousand arrested during clashes between the opposition and police.
Venezuelans continue to struggle with a failing economy, and severe shortages of food, power, water, and medicine.
TRT World's Latin American correspondent Juan Carlos Lamas reports from Caracas.
President Nicolas Maduro accuses the opposition of generating chaos with its protests. His supporters have also taken to the streets to rally against what they call a violent agenda against the socialist government.
Thousands of opponents of the leftist government marched to jails on Friday demanding the release of opposition leaders they say are political prisoners in the country's deadly crisis.
The rally was the latest in a month of demonstrations that left 29 people dead in clashes between riot police and anti-government protesters.
The country's opposition is demanding elections, autonomy for the legislature where they have a majority, a humanitarian aid channel from abroad to alleviate an economic crisis, and freedom for more than 100 jailed anti-government activists.
A crowd yelling "Freedom!" rallied near the Ramo Verde prison on the outskirts of Caracas.
That is where the most prominent of the prisoners, Popular Will party leader Leopoldo Lopez, is being held.
Supporters say Lopez, the US-educated leader of hardline Popular Will party, and others are political prisoners who symbolise President Nicolas Maduro's lurch into dictatorship.
Maduro says all are behind bars for legitimate crimes, and calls Lopez, 45, a violent hothead intent on promoting a coup.
"This shows yet again the fear Nicolas Maduro has of people in the street," said Popular Will legislator Juan Mejia at the National Guard barriers outside Ramo Verde jail.
Government officials accuse the opposition of inventing torture stories to sway international opinion against the Maduro government and create the conditions for a foreign intervention of the South American oil producer.
Lopez was arrested in 2014 and later sentenced to 14 years on charges of inciting violence during deadly riots.
A lead prosecutor in the case later alleged irregularities in his conviction.
Lopez's wife, Lilian Tintori, has become one of the international faces of Venezuela's political crisis.
She has traveled to meet with foreign officials to raise awareness of her husband's fate.
"They did not let us go to see Leopoldo... We have gone a month without seeing or hearing him," she told reporters near the prison.