Three American citizens, two Spaniards and a Czech citizen have been detained in Venezuela on suspicion of plotting to destabilize the country through “violent actions,” the government said Saturday, adding that hundreds of weapons had been seized.

The Venezuelan government identified the men detained on Saturday in an online video. One of them was identified as an American Navy sailor detained in Venezuela earlier this month while visiting the country on personal travel, several U.S. officials confirmed to CBS News. The enlisted sailor is a petty officer first class and formerly a Navy SEAL who was assigned to a West Coast team, several U.S. officials and a senior Defense Department official told CBS News. 

A State Department spokesperson told CBS News in a statement Saturday that the Biden administration could confirm the detention of the sailor and was “aware of unconfirmed reports” of the detentions of two other U.S. citizens. 

Interior Minister Diosdado Cabello said that the five were held on suspicion of planning an attack on President Nicolas Maduro and his government. The arrests come amid heightened tensions between Venezuela and both the U.S. and Spain over Venezuela’s disputed July 28 presidential election, which the country’s opposition accuses Maduro of stealing.

“Any claims of U.S. involvement in a plot to overthrow Maduro are categorically false,” the State Department spokesperson said. “The United States continues to support a democratic solution to the political crisis in Venezuela.

Maduro, a former bus driver, who succeeded iconic left-wing leader Hugo Chavez on his death in 2013, insists he won a third term but failed to release detailed voting tallies to back his claim.

“We know that the United States government has links to this operation,” Cabello asserted. He said the 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 United States and Spain as well as to Venezuelan opposition leader Maria Corina Machado.

“They contacted French mercenaries, they contacted mercenaries from Eastern Europe and they are in an operation to try to attack our country,” he said.

He added that “more than 400 rifles were seized” and accused the detainees of plotting “terrorist acts.”

The United States, Spain and the Czech Republic had yet to react to the sensational claims, which come amid a deepening standoff between Maduro and Western powers. A plane belonging to Venezuelan President Nicolás Maduro was seized by the U.S. and brought to Florida, the Justice Department said, claiming the jet was exported from Florida in violation of U.S. sanctions.

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 United States, 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 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. Maduro’s claim to have won a third term in office sparked mass opposition protests, which claimed at least 27 lives and left 192 people wounded.

The opposition published polling station-level results, which it said showed Gonzalez Urrutia winning by a landslide. About 2,400 people, including numerous teens, were arrested in the unrest. After Venezuela’s last election, in 2018, Maduro also claimed victory amid widespread accusations of fraud. With the support of the military and other institutions, he managed to cling to power despite international sanctions.

Maduro’s tenure since 2013 has seen GDP drop 80 percent in a decade, prompting more than seven million of the country’s 30 million citizens to migrate.

contributed to this report.