Venezuelan authorities announced Sunday that they've arrested six individuals suspected of involvement in the assassination attempt against President Nicolas Maduro.

"The responsible parties, both those who carried out the attack and those who supported it, both in the country and outside, have been identified. And there will be more arrests in the coming hours," said Interior Minister Nestor Luis Reverol.

The act is also seen as an attempt to murder those present, including civilians, public officials, high-ranking military officials and various ministers, he added.

The attack happened during a speech given by Maduro on Saturday to commemorate the 81st anniversary of Venezuelan National Guard when drones exploded near Maduro and his wife. Maduro escaped unharmed from the attack.

Maduro blamed the attack on the far-right factions in Venezuela, the Colombian government and conspirators in the United States, saying they were responsible.

On Sunday, Colombian foreign ministry refuted Maduro's accusation, saying in a statement that "the claims that the Colombian leader could be responsible for a supposed assassination of the Venezuelan president sound absurd and lack basis."

Venezuela-Colombia relationship has been long strained by frictions between the two neighbouring South American countries, including border disputes and military concerns.

Also in response, U.S. National Security Advisor John Bolton said on Sunday that the U.S. government was not involved in the assassination plot.

"I can say unequivocally there was no U.S. government involvement in this at all," Bolton told "Fox News Sunday."

Bolton said he had spoken to the U.S. charge d'affaires in Caracas and was told that "Americans are accounted for."

Venezuela's right-wing opposition groups have launched waves of protests in recent years designed to pressure the government to hold early presidential elections in a bid to oust Maduro.

Venezuelan Minister of Defense Vladimir Padrino Lopez on Sunday condemned the assassination attempt and proclaimed the military's unfaltering loyalty to the president.

Lopez called the attempt a "terrorist act" and a "desperate act" that are part of "destabilizing plans" to overthrow Maduro's government, which is "constitutionally legitimate and elected by the popular vote."

Oil-producing Venezuela has been struggling with an acute economic crisis since crude oil prices crashed in the international market, affecting state coffers and government-run services, including electricity and water.

Xinhua