Two Americans were detained in Venezuela on Monday on suspicion of plotting to topple President Nicolas Maduro's government, which has accused US-backed opposition leader Juan Guaido of bankrolling the scheme.
The arrests came a day after the government said it foiled an "invasion" from the sea, killing eight assailants and capturing two others.
Mr Maduro appeared on state television to show the passports of Luke Denman, 34, and Airan Berry, 41, and told the Venezuelan military high command that the pair were members of the US security forces.
Attorney General Tarek William Saab earlier told reporters that "hired mercenaries" had signed a $212 million dollar contract with Mr Guaido using funds "stolen" from state oil company PDVSA.
The United States - one of more than 50 countries backing Guaido as Venezuela's acting president as he challenges Mr Maduro for power - has slapped sanctions on PDVSA and allowed Mr Guaido to use funds from frozen accounts belonging to the firm's Houston-based subsidiary Citgo.
Mr Saab said Mr Guaido had signed a contract with former US special forces soldier Jordan Goudreau, linked in several press reports last week to an allegedly bungled attempt to topple Mr Maduro.
The Canadian-born Goudreau, an Iraq and Afghanistan veteran, is accused of training a mercenary force to invade Venezuela that disbanded after Colombian authorities seized a weapons shipment meant for the group.
Mr Saab also shared on social media a video of Mr Goudreau, who now runs a private security firm called Silvercorp USA, in which the former soldier claims an operation against Mr Maduro's regime is ongoing.
Mr Guaido's press team released a statement on Monday denying the accusations and insisting it had no agreements with private security firms.
On Sunday, Venezuela claimed a group traveling on speedboats and embarking from Colombia tried to land before dawn in the northern coastal state of La Guaira but were intercepted by the military and special police units.
Diosdado Cabello, deputy leader of the ruling Socialist Party, claimed the operation was "orchestrated" by the United States and its Drug Enforcement Agency (DEA), with Colombian support.
Colombia denied any involvement, while Mr Maduro claimed on Monday that the mission's aim was to assassinate him.
Venezuela frequently accuses Colombia of fomenting plots to overthrow the Maduro government and of allowing mercenaries to train in its territory.
Saab said authorities had detained 114 people and issued warrants for the arrest of 92 others accused of involvement in plots against Maduro and his regime since an alleged assassination attempt using explosives-laden drones in 2018.
He added that Venezuela had seized arms during the apparent invasion that were stolen from parliament during a failed military uprising led by Mr Guaido last year.
The public prosecutor has launched a number of investigations against Mr Guaido but has never ordered his arrest.
