PUERTO ORDAZ, Venezuela — Venezuela’s intelligence police detained the chief of staff of the opposition leader Juan Guaidó early Thursday, a significant escalation of the country’s political crisis and one that could provoke fresh punitive measures from the United States.
The chief of staff, Roberto Marrero, a lawyer and confidant of Mr. Guaidó’s, was taken from his apartment in southern Caracas around dawn to an unknown destination by armed intelligence officers, said Sergio Vergara, an opposition lawmaker who is a friend and neighbor of Mr. Marrero’s.
Mr. Guaidó and the National Assembly confirmed the detention in posts on Twitter.
Mr. Vergara said that Mr. Marrero told him as he was led away that the police had planted two rifles and a grenade in his house as a pretext to charge him with terrorism. Mr. Vergara, who is a member of Mr. Guaidó’s party, said that armed intelligence officers had also broken into his apartment and searched his house for several hours.
His claim could not be independently verified, and the country’s Information Ministry did not immediately respond on Thursday to a request for comment. But the government has used similar tactics in the past to jail other opposition figures.
The detention of Mr. Marrero is President Nicolás Maduro’s most serious attack yet on Mr. Guaidó’s camp. Mr. Guaidó drew international support from the United States and about 50 other countries when he declared himself Venezuela’s interim president in January.
The Trump administration has said that any repressive measures against Mr. Guaidó or his inner circle would be punished.
On Thursday, Secretary of State Mike Pompeo said on Twitter: “The United States condemns raids by Maduro’s security services and detention of Roberto Marrero, Chief of Staff to Interim President @jguaido. We call for his immediate release. We will hold accountable those involved.”