The head of Venezuela's secret police has broken ranks with embattled President Nicolas Maduro as the country braces for a second day violence following the turmoil surrounding a military uprising.

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

In a possible sign that Maduro's inner circle could be fracturing, the head of Venezuela's secret police wrote a letter on Tuesday breaking ranks with the embattled leader.

In a letter directed to the Venezuelan people, Manuel Ricardo Cristopher Figuera - the head of Venezuela's feared SEBIN intelligence agency - said he had always been loyal to Maduro but now it is time to 'rebuild the country'.

Violent street battles erupted in parts of Caracas on Tuesday in what was the most serious challenge yet to embattled Venezuela President Nicolas Maduro

In a possible sign that Maduro's inner circle could be fracturing, the head of Venezuela's secret police - Manuel Ricardo Cristopher Figuera - wrote a letter on Tuesday breaking ranks with the embattled leader

He said corruption has become so rampant that 'many high-ranking public servants practice it like a sport'.

'The hour has arrived for us to look for other ways of doing politics,' Figuera wrote.

The authenticity of the letter circulating on social media was confirmed by a senior U.S. official.

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 U.S. and neighboring Colombia.

Maduro said that the unrest had been quelled and that Venezuela wouldn't succumb to right-wing forces intent on 'submitting our country to a neocolonial economic domination model and enslaving Venezuela.'

'Now you can see a Venezuela largely in peace,' he proclaimed.

Venezuelans waited to see if that remained the case Wednesday.

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.

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

Opposition leader Juan Guaido took a bold step to revive his movement to seize power in Venezuela, taking to the streets on Tuesday to call for a military uprising

Supporters of President of the Venezuelan Parliament, Juan Guaido, clash with the National Bolivarian Police during a protest in Caracas on Tuesday

Opposition leader Juan Guaidó 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 but also fierce resistance from forces loyal to embattled socialist Nicolas Maduro

He called it the moment for Venezuelans to reclaim their democracy once and for all but as the hours dragged on Guaido stood alone on a highway overpass with the same small cadre of soldiers with whom he launched a bold effort to spark a military uprising.

Like past attempts to oust Maduro, the opposition seemed outmaneuvered again on Tuesday.

What Guaido dubbed 'Operation Freedom' triggered a familiar pattern of security forces using repressive tactics to crush small pockets of stone-throwing youths while millions of Venezuelans watched the drama unfold with a mix of fear and exasperation.

The opposition's hoped-for split in the military didn't emerge, a plane that the U.S. claimed was standing by to ferry Maduro into exile in Cuba never took off and by nightfall one of the government's bravest opponents, who defied house arrest to join the insurrection, had quietly sought refuge with his family in a foreign embassy.

Guaidó, the telegenic 35-year-old leader of the opposition-dominated congress who is recognized by the U.S. and over 50 nations as Venezuela's rightful president, nonetheless pressed forward in calling for a new round of mass street protests Wednesday.

Opposition forces are hoping that Venezuelans angered by broadcast images of armored vehicles plowing into protesters and fed up with their nation's dire humanitarian crisis will fill streets across the nation.

'We need to keep up the pressure,' Guaidó said. 'We will be in the streets.'

The latest chapter in Venezuela's political upheaval marks the most serious threat yet to Maduro's contested rule.

The leader, who has been relying on support from Russia and China, was largely absent as events unfolded Tuesday. He finally emerged late in the evening to call the small-scale uprising a failed U.S.-backed coup attempt.

In one dramatic incident during a chaotic day, several armored vehicles plowed into a group of anti-government demonstrators during clashes with the Venezuelan National Guard

An anti-government protester walks near a bus that was set on fire by opponents of Venezuela's President Nicolas Maduro during clashes between rebel and loyalist soldiers in Caracas on Tuesday

The turmoil Tuesday began when Guaidó, flanked by a few dozen national guardsmen and some armored crowd-control vehicles, released a 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 following an order from Guaidó.

'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 Guaidó at a plaza a few blocks away. A smaller group of masked youths stayed behind on the highway, lobbing rocks and gasoline bombs toward the air base and setting a government bus on fire.

'It's now or never,' said one of the young rebellious soldiers, his face covered in the blue bandanna worn by the few dozen insurgent soldiers.

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 armored vehicles sped away dodging gasoline bombs thrown by the demonstrators.

The head of a medical center near the site of the street battles said doctors were treating over 50 people, about half of them with injuries suffered from rubber bullets. At least one person had been shot with live ammunition. The Venezuelan human rights group Provea said a 24-year-old man was fatally shot during an anti-government protest in the city of La Victoria.

Later Tuesday, Lopez and his family sought refuge in the Chilean ambassador's residence and later moved to the Spanish Embassy. There were also reports that 25 soldiers who had been with Guaidó fled to Brazil's diplomatic mission.