CARACAS, Venezuela — Venezuela plunged deeper into turmoil Monday as security forces put down a pre-dawn uprising by national guardsmen that triggered violent street protests, and the Supreme Court moved to undercut the opposition-controlled congress’ defiant new leadership.

Socialist party chief Diosdado Cabello said 27 guardsmen were arrested and more could be detained as the investigation unfolds.

The mutiny struck at a time when opposition leaders have regained momentum in their efforts to oust President Nicolas Maduro. They have called for a nationwide demonstration Wednesday, urging Venezuelans — especially members of the armed forces — to abandon Maduro.

The uprising triggered protests in a poor neighborhood just a few miles (kilometers) from Venezuela’s presidential palace. It was dispersed with tear gas as residents set fire to a barricade of trash and chanted demands that Maduro leave power.

The military said in a statement said that it had recovered all the weapons and captured those involved in what it described as “treasonous” acts motivated by “obscure interests tied to the far right.”

It said at around 2:50 a.m., a small group of guardsmen took captive a captain in charge of a police station in western Caracas and then moved across the capital in two military trucks to the poor neighborhood of Petare, where they stole a cache of weapons from another outpost.

Officials said 25 soldiers were quickly caught at the National Guard outpost 2 miles from the Miraflores presidential palace, and two more arrests were made at another location.

A few hours earlier, a group of heavily armed national guardsmen published a series of videos on social media saying they won’t recognize Maduro’s government, which has come under increasing domestic and international pressure over a newly begun second term that the opposition-controlled congress and many nations consider illegitimate.

In one of the videos, a man identifying himself as 3rd Sgt. Alexander Bandres Figueroa, addressing the “people of Venezuela,” urges his compatriots to take to the streets to show support for their rebellion.

“You asked to take to the streets to defend the constitution, well here we are,” he said in a video shot at night in which several heavily armed men and a national guard truck can be seen in the background.

“You wanted us to light the fuse, so we did. We need your support,” he added.

At daybreak in the adjacent neighborhood of Cotiza, a group of shirtless young men, some with their faces covered, built a barricade across the street with a burning car, heavy sewer grates and a large chunk of concrete.

An angry group of women shouted that they have lived for too long without running water and tear gas fired by security forces choked their children.

“Freedom! Freedom!” they chanted. “Maduro has to go!”

“We must defend our homeland,” Maria Fernanda Rodriguez, a 36-year-old manicurist, told The Associated Press, her eyes welling from the tear gas.

Hours later, the government-stacked Supreme Court said it was throwing out recent measures by the National Assembly that declared Maduro’s presidency illegitimate, deepening a standoff with the opposition-controlled legislature.