Venezuelan President Hugo Chavez has accused US embassy staff of espionage and says Venezuelan agents have infiltrated the alleged spy ring.
Hugo Chavez says any US spies will be arrested
"We have you infiltrated ambassador, don't move much because we are watching you," the president announced.
The claims follow accusations that some Venezuelan naval officers have passed information through the US embassy.
Mr Chavez has repeatedly accused the US of supporting attempts to overthrow him, an allegation Washington denies.
In his latest comments, at the launch of a new company to co-ordinate the government's growing industrial activities, he urged the US ambassador, William Brownfield, to "stop spying".
"The military officers of the US embassy are involved in espionage and we have them infiltrated," he added.
Mr Chavez threatened last week to have any American officials involved in spying arrested.
US embassy officials say they have not been contacted on the latest accusations or told the details of any charges.
The US state department has called the charges a domestic matter for Venezuela.
Venezuelan Vice-President Jose Vicente Rangel said some of the Venezuelan officers concerned had been detained and others had left the country.
He did not disclose the number of people involved in the alleged spying, or the kind of information they were said to have passed on.