CARACAS, Venezuela (Reuters) - Venezuelan authorities overnight freed two activists who were in jail for more than a year after being accused of plotting against socialist President Nicolas Maduro, the opposition said on Saturday.

Delson Guarate, who had been a mayor in central Aragua state, and former student leader Yon Goicoechea were among nearly 400 jailed anti-Maduro activists who rights campaigners say are political prisoners but whom the government calls coup-plotters.

“I’m with my family today,” tweeted Goicoechea, displaying a photo of himself against the backdrop of Caracas’ Avila mountain. “Tomorrow I’ll address the country. God is with us.”

“I’m free!” Guarate tweeted.

The pair’s freedom, with some unspecified conditions attached, was confirmed by opposition parties and a rights group, but the government had no comment.

The releases came as Maduro called for one of the most prominent opposition leaders, congress head Julio Borges, to face treason charges for lobbying against his government in global financial circles.

And the pro-Maduro Supreme Court began moves this week to remove parliamentary immunity for congress deputy leader Freddy Guevara, so he can be tried for instigating violence.

Guevara runs the militant Popular Will party, which both Goicoechea and Guarate belong to. It has been at the forefront of anti-Maduro protests, including four months of demonstrations this year that led to 125 deaths.

Critics say Maduro has turned the OPEC nation into a dictatorship. His supporters say the 54-year-old successor to Hugo Chavez is resisting a Western-backed push to oust him.

In a New York Times column earlier this year, Goicoechea described how a dozen policemen put a black cloth over his head when they arrested him before taking him to a cell without natural light or ventilation.

“When I stretched my arms, I could touch two opposite walls,” he wrote in the column smuggled out of prison. “The door was blocked with black garbage bags, leaving the room in total darkness.

“There was rotten, worm-infested food on the floor alongside scraps of clothing covered in feces. It felt as if I had been buried alive.”

Senior officials said Goicoechea was an “imperialist” agent caught with explosives in his possession, while Guarate had been financing “terrorism.” Neither was tried.

Popular Will, which the government has threatened to proscribe as a terrorist organization, said it would not stop fighting for the freedom of all activists.

“The dictatorship’s ‘justice’ is a revolving door,” said party legislator Juan Mejia. “Some leave, while others come in at its discretion and to its benefit.”