Venezuelan President Nicolas Maduro reacts during an event which was interrupted, in this still frame taken from video August 4, 2018, Caracas, Venezuela.
Communication Minister Jorge Rodriguez said there was "an explosive charge. detonated close to the presidential podium" and in several other spots along the parade held in central Caracas.
State television Maduro abruptly cutting short a speech, causing hundreds of soldiers present to break ranks and scatter.
Mr Maduro "came out of it completely unharmed and at this moment is carrying out his normal duties and is in permanent contact with senior political officials, with ministers and with senior military chiefs", Mr Rodriguez said.
"This was an attempt to kill me", he said later in an impassioned retelling of the events. Maduro accused current Colombian President Santos of being behind the assassination attack with others involved. The audio then cut off. Dozens of soldiers were seen running away before the broadcast was halted.
Maduro, who escaped unhurt in the incident, said "everything points" to a right-wing plot against him and also claimed arrests have been made in the case.
Maduro has claimed he is battling an imperialist plot to destroy socialism and take over Venezuela's oil revenues.
Trump marks Kelly's one-year mark as departure rumors swirl
Speculation about his exit has flared for months, amid reports that Trump had cooled on the retired four-star general. But Trump has made a decision to stick with Kelly - for now, at least.
He added: "Whoever carried out this attack, failed".
No group has said it was behind the alleged assassination attempt.
The attack comes as the nation struggles with an economic crisis.
AP reports that firefighters at the scene of the explosion are disputing the Government's version of events.
The organization did not respond to a message from The Associated Press seeking more information.
Images being shared on social media showed officers surrounding Maduro with what appeared to be a black bullet-proof barrier as they escorted him from the site.
"We showed that they are vulnerable", the group said in a tweet. "We didn't have success today, but it's just a question of time", it said. Writing on Twitter, he said: "We strongly repudiate a new aggression and cowardly attack on Nicolas Maduro and the Bolivarian people".