Venezuelan authorities said Sunday that they have detained six people allegedly connected to what President Nicolás Maduro claimed was an assassination attempt, and what other leaders have deemed a terrorist attack.
Venezuela, a once-wealthy oil-producing nation, is in the midst of a five-year crisis under Maduro's socialist government. Opposition leaders decried Maduro for broadly singling out his political opponents, and they warned he may use it to further suppress his critics.
The suspects launched two drones laden with explosives over an outdoor rally Maduro was holding in downtown Caracas to commemorate the National Guard, Interior Minister Nestor Reverol said.
"I heard the first explosion, it was so strong that the buildings moved", said Mairum Gonzalez, 45, a pre-school teacher. In a series of posts on social media, the group said that it had planned to fly two drones but that military snipers shot them down.
One of those arrested was wanted in connection with an earlier attack on a military installation, Reverol said. "In the next hours there could be more arrests".
At least 58 people were killed in protests against the government in July 2017.
The attack highlights Maduro's challenges in maintaining control over the OPEC nation, where widespread food and medicine shortages have fuelled outrage and despair everywhere from hillside slums to military barracks.
Bolton said he spoke with the US government's top diplomatic official in Caracas, the Venezuelan capital, on August 5 and said that Americans in Venezuela are safe. Several vehicles have been seized and hotel rooms searched as part of the investigation.
Venezuela's Minister of Communication, Jorge Rodriguez, said an initial investigation showed that the explosions came from several "drone-type flying devices", but NBC news reported they were thought to be off-the-shelf commercial drones.
One witness showed The Associated Press cellphone video of a drone crashing into a building.
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"I am fine, I am alive, and after this attack I´m more determined than ever to follow the path of the revolution", said the 55-year-old.
The drones, according to officials, were flown towards Maduro as he addressed soldiers in Caracas on Saturday.
Within seconds, Maduro said he heard a second blast and pandemonium broke out.
"These terrorist acts represent a slap in the face to the expressed desire of the President of the Republic, Nicolas Maduro, for national reconciliation and dialogue", Reverol said in a statement read on state television. He pointed the finger at outgoing Colombian President Juan Manuel Santos and "the ultra-right wing" - a term he uses to describe domestic opposition, even as a mysterious rebel group claimed responsibility.
The Colombian government was quick to deny any involvement, saying there was "no basis" to Mr Maduro's allegations.
Maduro, who blames the country's problems on an "economic war" led by adversaries, during the course of his five-year rule has often announced having foiled military plots against him that he says are backed by Washington.
Apparently in response, Bolton said, "If the government of Venezuela has hard information that they want to present to us that would show a potential violation of USA criminal law, we'll take a serious look at it".
"It's evident that the initial reaction of the government isn't aimed at attempting to clarify what happened but rather to take advantage of the situation and irresponsibly and sweepingly attack the 'opposition, '" the group said in a statement.
Signs of smoke cover the apartment complex where an allegedly armed drone crashed, causing a fire, in Caracas, Venezuela, Sunday, Aug. 5, 2018. The AP could not independently verify the authenticity of the message. "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".
Venezuela's government routinely accuses opposition activists of plotting to attack and overthrow Maduro.