Demonstrators clashed violently with police on the streets of the Venezuelan capital on Tuesday, spurred by opposition leader Juan Guaido's call on the military to rise up against President Nicolas Maduro, whose government said it was putting down an attempted coup.
An apparently carefully planned attempt by Guaido to demonstrate growing military support disintegrated into rioting as palls of black smoke rose over eastern Caracas.
The government said it was deactivating an attempted coup by a small group of treacherous soldiers.
As rioting and confusion raged, there was little early sign Maduro's iron grip on the military - which has kept him in power in a months-long standoff with Guaido - had slipped. On Twitter, he claimed the military chiefs had assured him of their total loyalty.
Guaido rallied his supporters with an early morning video message that showed him - for the first time - with armed troops he said had heeded months of urging to join his campaign to oust Maduro.
The 35-year-old National Assembly leader was filmed outside the La Carlota air base, where he urged the armed forces inside to join him.
The video had the extra shock value of featuring key opposition figure Leopoldo Lopez at his side, saying he had been released from years of house arrest by soldiers.
Guaido claimed the move was the beginning of the end of Maduro's regime, and there was no turning back.
Thousands of opposition supporters flocked onto a highway near the base, many waving Venezuelan flags. But confusion reigned as they were met with gunfire and tear-gas fired by soldiers at the perimeter of the base.
Lopez later entered the Chilean embassy with his wife and one of his children to claim asylum, Chile's Foreign Minister Roberto Ampuero announced in Santiago. But finally he entered the Spanish embassy given his EU country background.
Soldiers backing Guaido wore blue armbands to demonstrate their allegiance to the opposition leader - recognized as interim president by more than 50 countries - but there appeared to be few of them.
Brazil said later a number of Venezuelan troops had sought asylum at its Caracas embassy.
Maduro had called on his forces to show nerves of steel and troops in riot gear, backed by armored vehicles and water tankers, lined up against the demonstrators on a highway wreathed in tear-gas.
Several of the vehicles ran into the crowd, injuring some of the protesters. Rioters later blocked the highway with a bus and set it on fire.
A pall of black smoke rose from an area near a helicopter hangar on the base, but demonstrators who briefly managed to enter the base were pushed back.
As UN Secretary General Antonio Guterres appealed to all sides to avoid violence, Venezuela's army chief and defense minister, General Vladimir Padrino, issued a stark warning of possible bloodshed - adding that he would hold the opposition responsible.
In a message on Twitter, Padrino said the situation in military barracks and bases in the country was normal, amid reports of demonstrations in Maracaibo and other cities.
He later said an army colonel had received a bullet wound to the neck during the clashes in Caracas.
A teenager and at least 69 people were injured in the clashes, two from gunshot wounds, according to Venezuela's health services.
The US, meanwhile, threw its full support behind Guaido, with the White House calling on the military to protect the people and support the country's legitimate institutions, including the opposition-controlled National Assembly.
Russia, Maduro's main backer and creditor with China, accused Guaido of fueling conflict in the oil-rich country.
Maduro's leftist Latin American allies Cuba and Bolivia also condemned Guaido.
President Ivan Duque of neighbouring Colombia - home to more than a million refugees from Maduro's regime -- called on Twitter for soldiers and the people of Venezuela to place themselves on the right side of history, rejecting dictatorship and Maduro's usurpation.
The government suspended broadcasts from BBC Mundo, CNN International and a Caracas radio station, local media and the National Union of Press Workers said.