Several drones loaded with explosives exploded close to where President Nicolas Maduro was speaking, says Venezuela's information minister.
At least one explosion rocked a military event where Venezuelan President Nicolas Maduro was giving a speech on Saturday and the government said it was a failed assassination attempt involving drones carrying explosives.
Maduro, a leftist who replaced President Hugo Chavez after his death in 2013, was unharmed but Information Minister Jorge Rodriguez said seven National Guard soldiers were injured.
Maduro said "everything points" to a right-wing plot that initial investigation suggested was linked to Colombia and the US state of Florida, where many Venezuelan exiles live. Several perpetrators were caught, he said, without elaborating.
Rodriguez said drones loaded with explosives detonated close to the military event in downtown Caracas. A Venezuelan who was visiting family nearby told Reuters she heard two explosions.
TRT World's Reagan Des Vignes reports.
"This was an assassination attempt, they tried to assassinate me," Maduro said in a later televised address.
Venezuela's opposition on Sunday warned that the government of Maduro may launch a political crackdown after his government accused adversaries of seeking to assassinate him.
Juan Carlos Lamas spoke to TRT World from Caracas about the events that unfolded.
"They are vulnerable"
A little-known group called the "National Movement of Soldiers in T-shirts" claimed responsibility for the attack. In a series of posts on social media, the group said it had planned to fly two drones but that snipers shot them down.
"We demonstrated that they are vulnerable. We didn't have success today, but it's just a question of time," said the group, which says it was founded in 2014 to bring together all of Venezuela's "groups of resistance."
The group did not respond to several requests for information from Reuters.
US denies any involvement
A senior White House official on Sunday denied the United States was behind the drone blast.
"I can say unequivocally there is no US government involvement in this at all," said John Bolton, national security adviser to the White House, told "Fox News Sunday" in an interview.
Bolton suggested that the Maduro government could be behind the explosion, citing widespread corruption and oppression in Venezuela.
"It could be a lot of things from a pretext set up by the Maduro regime itself to something else," Bolton said, adding that there were no Americans injured in the blast.
"If the government of Venezuela has hard information that they want to present to us that would show a potential violation of US criminal law, we will take a serious look at it," he added.
It came after Maduro said initial investigations indicated that "several of those intellectually responsible and the financiers of this attack live in the United States, in the state of Florida." He called on US President Donald Trump to "fight these terrorist groups."
Maduro blames Colombia's Santos
Maduro won a new six-year term in May but his main rivals disavowed the election and alleged massive irregularities.
Venezuela is suffering under the fifth year of a severe economic crisis that has sparked malnutrition, hyperinflation and mass emigration.
Maduro named Colombian President Juan Manuel Santos as being behind the attack, but gave no evidence to back that up.
"The name of Juan Manuel Santos is behind this attack ... the initial investigations point to Bogota," Maduro said.
A Colombian government source said Maduro's allegation was "absurd" and that Santos was celebrating his granddaughter's baptism on Saturday. "He is not thinking of anything else, least of all bringing down foreign governments," the source said.
During the incident, Maduro was speaking about Venezuela's economy in an address when audio of the live television coverage was suddenly cut off.
Maduro and others on the podium looked up startled and the cameras panned to soldiers who had been lined up in formation in the street. Scores of them ran in panic away from one area.
Caught by surprise mid-speech, Maduro and his wife, Cilia Flores, looked up at the sky and winced Saturday after hearing the sound of an explosion pierce the air.
Photographs on social media appeared to show bodyguards shielding Maduro with black bulletproof panels. A photograph also showed an injured military official clutching his bloody head and being held up by colleagues.
OPEC member Venezuela's once-thriving socialist economy has collapsed since the 2014 fall of oil prices.
The self-described "son" of Chavez, former bus driver Maduro says he is battling an "imperialist" plot to destroy socialism and take over Venezuela's oil. Opponents accuse him of authoritarianism, saying he has destroyed a once-wealthy economy and ruthlessly crushed dissent.
Fahrettin Altun, the Communications Director for the Turkish Presidency, said: "We condemn the assassination attempt against Venezuelan President Nicolas Maduro. Turkey stands with the people of Venezuela and their democratically elected leader. We wish a speedy recovery to Mr. President and Venezuela."
We condemn the assassination attempt against Venezuelan President Nicolas Maduro.— Fahrettin Altun (@fahrettinaltun_) August 5, 2018
Turkey stands with the people of Venezuela and their democratically elected leader.
We wish a speedy recovery to Mr. President and Venezuela.
Bolivian President Evo Morales said: "This attempt at assassination, which is a crime against humanity, only shows the desperation of an empire defeated by a brave people. Our solidarity."
Este intento de magnicidio, que es un delito de lesa humanidad, solo muestra la desesperación de un imperio derrotado por un pueblo valiente. Nuestra solidaridad. ¡Fuerza hermano presidente @NicolasMaduro y pueblo bolivariano!— Evo Morales Ayma (@evoespueblo) August 5, 2018
Last year, a rogue Venezuelan police officer hijacked a helicopter and fired at government buildings in what he said was an action against a dictator. The officer was hunted down and killed by Venezuelan forces.