Live footage of the event showed him suddenly looking up startled mid-speech, while beside him his wife, Cilia Flores, winces after a loud bang.
Dozens of soldiers are also seen scattering during the event to commemorate the 81st anniversary of the Venezuelan national guard in the capital of Caracas.
Seven members of the national guard were hurt during the attack, which the president blamed on far-right elements and Colombia’s outgoing president, Juan Manuel Santos.
A Colombian presidential source told CNN that Maduro’s accusations were “baseless.”
“I’m alive and victorious,” Maduro said in a national television address hours after what he described as an assassination attempt.
The president added that there were two explosions, seconds apart, and that he initially thought they were fireworks as part of the military parade.
Venezuela’s Minister of Communication, Jorge Rodriguez, said preliminary information showed the explosions came from several “drone-type flying devices” containing explosive charges that detonated in the vicinity of the presidential stage and in some areas of the parade.
A photo posted on Twitter by Freddy Nanez, head of the Venezuelan state run news channel VTV, shows bodyguards shielding Maduro following the explosions.
Venezuela’s attorney general, Tarek William Saab, told CNN he had ordered an investigation into the incident, assigning three prosecutors to the investigation.
Saab was close to the president during the event, and says the drone responsible for filming the event exploded. He added that a second explosion followed.
During his speech to the nation following the incident, Maduro said the investigation started immediately and that some of those involved in the attack had already been captured and charged, although he did not specify the charges against them.
Speaking in front of members of the military and other government officials, Maduro also said that authorities were able to obtain evidence of the attack and said the investigation was in an advanced stage.
He blamed the Venezuelan political far right in collaboration with the Colombian far right, and the current Colombian President Santos of being behind the assassination attack.
He also blamed Venezuelans living in the US.
“The preliminary investigation indicates that many of those responsible for the attack, the financiers and planners, live in the United States in the state of Florida,” Maduro said.
“I hope the Trump administration is willing to fight terrorist groups that commit attacks in peaceful countries in our continent, in this case Venezuela.”
The Venezuelan government has long blamed Colombia for plotting overthrows and, and far-right elements in Bogota and Miami for attempting to undercut Maduro. Ivan Duque takes over as the Colombian President next week.
A Colombian presidential source told CNN that Maduro’s accusations were “baseless,” adding Santos was “dedicated to his granddaughter’s Celeste baptism, and not taking down foreign governments.”
A senior US State Department official traveling with US Secretary of State Mike Pompeo in Indonesia said the US “had heard the reports,” and was following closely.
How the remarkable attack unfolded
The military parade took over most of the Avenida Bolivar, one of the main thoroughfares in Caracas, and the president’s speech came toward the end of the event.
Video broadcast live on Venezuelan state-run news channel, VTV, showed Maduro talking about an economic recovery, when the audio cuts mid sentence.
Cilia Flores, Maduro’s wife, was standing next to him. She looks up and winces.
Shortly after, VTV shows video of soldiers and National Guardsman scattering along the avenue.
Manuel Berbín lives nearby and told CNN en Español that he and his wife thought the first explosion were fireworks.
“We heard the first explosion, and we were there thinking that it could have been a firework that exploded close to our apartment” he said. “Then we heard the second explosion, that was very strong. We went to the window, and at that time we saw the soldiers start to run, they started to move the cars quickly, the sirens started going.”
Berbin says he saw smoke rising from the area shortly after.
He adds the explosions were very close to each other.
CNN’s Sheena McKenzie, Radina Gigova and Elise Labott contributed to this report. CNN en Español’s Rafael Romo and Abel Alvarado contributed to this report.