Caracas, Venezuela - Three Americans, two Spaniards, and a Czech citizen were detained in Venezuela on suspicion of plotting to destabilize the country, the government said Saturday, as the US denied Caracas' allegations it was involved.

The arrests come amid heightened tensions between Venezuela and both the US and Spain over Venezuela's July 28 presidential election, which the country's opposition and former colonial powers accuse President Nicolas Maduro of stealing.

Interior Minister Diosdado Cabello said the foreign nationals were being held on suspicion of planning an attack on Maduro and his government.

"We know that the United States government has links to this operation," Cabello asserted.

Cabello said two Spaniards were recently detained in Puerto Ayacucho in the southwest. He added that three Americans and a Czech national were also arrested and linked the alleged plot to intelligence agencies in the US and Spain as well as to Venezuelan opposition leader Maria Corina Machado.

Maduro has blamed the adversity his country faces on the imperialist US, which he accuses of conspiring with his Venezuelan opponents to overthrow him.

A State Department spokesperson said Saturday that "any claims of US involvement in a plot to overthrow Maduro are categorically false."

The State Department spokesperson additionally confirmed that a US military member was being held and noted "unconfirmed reports of two additional US citizens detained in Venezuela."

Cabello, meanwhile, said that those detained had "contacted French mercenaries, they contacted mercenaries from Eastern Europe and they are in an operation to try to attack our country." He added that "more than 400 rifles were seized" and accused the detainees of plotting "terrorist acts."

Spain "denies and categorically rejects" allegations by Venezuela that Madrid was involved in a plot to destabilize the country.

Maduro, who succeeded iconic left-wing leader Hugo Chavez on his death in 2013, insists he won a third term in office – a result affirmed by the country's Supreme Court.

Tensions between Caracas and former colonial power Spain rose sharply after Venezuelan opposition candidate Edmundo Gonzalez Urrutia (75) went into exile in Spain a week ago, after being threatened with arrest.

Earlier this week, Caracas recalled its ambassador to Madrid for consultations and summoned Spain's envoy to Venezuela for talks after a Spanish minister accused Maduro of running a "dictatorship."

Venezuela was also angered by Spanish Prime Minister Pedro Sanchez's decision to meet with Gonzalez Urrutia and warned Spain against any "interference" in its affairs.

Caracas has additionally been engaged in a war of words with the US, which recognized Gonzalez Urrutia as the winner of the election.

Washington on Thursday announced new sanctions against 16 Venezuelan officials, including some from the electoral authority, for allegedly impeding "a transparent electoral process" and not publishing accurate results.

Venezuela denounced the measures as a "crime of aggression" and Maduro decorated four military officers among those targeted by the sanctions.

The US and the CIA have a long history of intervention and destabilization in Latin America, including the overthrow of democratically elected leaders.