Santos, who hands over power to elected successor Ivan Duque tomorrow, has categorically rejected the accusation. His government has labelled it "absurd." A live broadcast of the incident on Venezuelan state television showed Maduro interrupted in mid-speech by an explosion and looking up in confusion.
Dozens of soldiers on parade are then seen breaking ranks and running away in panic.
Maduro and his government said the president had been targeted by two flying drones carrying explosives. But details of the incident remain unclear, with conflicting information coming from various sources.
Maduro's critics said they feared the Venezuelan government would now step up repression of the opposition and dissidents.
Venezuelan Attorney General Tarek William Saab told a news conference on Monday that several suspects were in custody and authorities would track down all those who conspire against public peace."
He called the drone attack, in which seven soldiers were said to be wounded, "an attempted massacre." "Let this act serve to root out once and for all any sort of violent attempt to threaten the peace," Saab said.
He said two drones had been used, each carrying a kilogram of C4 explosive.
One went out of control and flew into a building, while the other was jammed and exploded before reaching the president's podium, Reverol said.
Maduro's supporters marched through Caracas today.
The 55-year-old Socialist leader was expected to address them in what would be his first public appearance since Saturday's incident.
No drones could be seen in the broadcast of the event, which was cut moments after the soldiers were seen scattering away from where Maduro was standing flanked by military chiefs and his wife.
Some accounts on the ground said a fire at a nearby building was caused by the accidental explosion of a gas cylinder.
An unauthenticated statement from a rebel group calling itself the "National Movement of Soldiers in T-Shirts" claimed responsibility in a statement passed to an opposition journalist based in the US.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)