CARACAS, Venezuela (AP) — Opposition leader Juan Guaido took a bold step to revive his movement to seize power in Venezuela, taking to the streets Tuesday to call for a military uprising that drew quick support from the Trump administration and fierce resistance from forces loyal to socialist Nicolas Maduro.

The violent street battles that erupted in parts of Caracas were the most serious challenge yet to Maduro’s rule. And while the rebellion seemed to have garnered only limited military support, at least one high-ranking official announced he was breaking with Maduro, in a setback for the embattled president.

In a Tuesday night appearance on national television, Maduro declared that the opposition had attempted to impose an “illegitimate government” with the support of the United States and neighboring Colombia. He said Venezuela had been a victim of “aggression of all kinds.”

Meanwhile, Guaido sought to keep the momentum going at the end of the day by releasing his own video message in which he pressed Venezuelans to take to the streets again on Wednesday.

The competing quests to solidify a hold on power capped a dramatic day that included a tense moment when several armored vehicles plowed into a group of anti-government demonstrators trying to storm the capital’s air base, hitting at least two protesters.

U.S. National Security Adviser John Bolton said the Trump administration was waiting for three key officials, including Maduro’s defense minister and head of the supreme court, to act on what he said were private pledges to remove Maduro. He did not provide details.

The stunning events began early Tuesday when Guaido, flanked by a few dozen national guardsmen and some armored crowd-control vehicles, released the three-minute video shot near the Carlota air base.

In a surprise, Leopoldo Lopez, Guaido’s political mentor and the nation’s most-prominent opposition activist, stood alongside him.

Detained in 2014 for leading a previous round of anti-government unrest, Lopez said he had been released from house arrest by security forces adhering to an order from Guaido.

“I want to tell the Venezuelan people: This is the moment to take to the streets and accompany these patriotic soldiers,” Lopez declared.

As the two opposition leaders coordinated actions from a highway overpass, troops loyal to Maduro fired tear gas from inside the adjacent air base.

A crowd that quickly swelled to a few thousand scurried for cover, reappearing later with Guaido at a plaza a few blocks from the disturbances. A smaller group of masked youths stayed behind on the highway, lobbing rocks and Molotov cocktails toward the air base and setting a government bus on fire.

Amid the mayhem, several armored utility vehicles careened over a berm and drove at full speed into the crowd. Two demonstrators, lying on the ground with their heads and legs bloodied, were rushed away on a motorcycle as the vehicles sped away dodging fireballs thrown by the demonstrators.