The United States said Tuesday it was "deeply concerned" about the detention of a human rights activist in Venezuela who stands accused of involvement in an alleged plot to assassinate President Nicolas Maduro.
The Spanish-Venezuelan lawyer and government critic Rocio San Miguel, 57, was detained on Friday in the immigration area of an airport in the capital Caracas.
Her detention comes in a crunch election year that has already seen Maduro block his main opposition rival, prompting the United States to threaten to reimpose recently eased oil sanctions.
San Miguel's defense team said she had been arrested in a "forced disappearance" alongside her ex-husband, while her daughter, two brothers and father had been detained and later released.
Attorney General Tarek William Saab wrote Monday on X that San Miguel was accused of "the crimes of treason, conspiracy, terrorism and association, among others."
Her ex-husband, retired soldier Alejandro Jose Gonzales De Canales Plaza, is being held for allegedly revealing "political and military secrets concerning the security of the nation," Saab added.
White House National Security Council spokesman John Kirby warned the administration of President Joe Biden was "deeply concerned" and was watching the situation "very, very closely."
He said Maduro "needs to meet the commitments that he made ... about how they're going to treat civil society, political activists as well as opposition parties."
EU spokeswoman Nabila Massrali called for San Miguel's immediate release.
But Saab slammed a "ferocious campaign from abroad against the justice system and the Venezuelan state."
- 'Plan to silence critics' -
Maduro's government and the opposition reached a deal in Barbados to hold a free and fair vote in 2024 with international observers present, prompting the United States to ease sanctions.
However, the Supreme Court, loyal to Maduro, recently upheld a 15-year ban on opposition primary winner Maria Corina Machado, prompting Washington to reimpose some sanctions.
The United Nations rights office's independent fact-finding mission to Venezuela denounced the arrests as part of a "wave of repression against opponents."
"These are not isolated incidents, but rather a series of events that appear to be part of a coordinated plan to silence critics and perceived opponents," said Marta Valinas, chairwoman of the mission, in a statement.
The detentions come after Venezuelan authorities in January said they had uncovered five plots to assassinate Maduro, implicating rights activists, journalists and soldiers.
Maduro frequently denounces plans to overthrow him, usually with the alleged involvement of the United States and the opposition.
Saab said San Miguel and her ex-husband were among six citizens alleged to be involved in the "White Bracelet" conspiracy. It was not clear if the other accused were the members of San Miguel's family.
"White Bracelet" is described by the government as a plan to attack a military base in Tachera, on the border with Colombia, as part of the alleged plot to kill Maduro.
San Miguel runs the non-governmental organization Citizen Control, which investigates security and military issues, such as the number of citizens killed by security forces.
In 2018, she won a case against Venezuela at the Inter-American Court of Human Rights for the violation of political rights and freedom of expression.
The case was linked to her dismissal in 2003 from a state entity after she backed a call for a referendum to recall then-president Hugo Chavez from office.
The Foro Penal NGO, which provides free legal assistance, says there are 261 political prisoners, including 18 women and 146 soldiers, in the country.