National guard units were posted at the entries and exits to the prosecutors' building in central Caracas. Photograph: (AFP)
Venezuela's contested new assembly fired the country's dissident attorney general, Luisa Ortega, Saturday in a move sure to provoke greater international criticism.
The body, which made the sacking its first order of business, also said it planned to operate as Venezuela's supreme power for up to two years.
Venezuela's dissident attorney general said Saturday her offices were "under siege" by troops, as a new loyalist assembly was about to start work to bolster the policies of President Nicolas Maduro and counter his foes.
National guard units were posted at the entries and exits to the prosecutors' building in central Caracas.
Attorney General Luisa Ortega, who broke ranks with Maduro months ago and has since been a thorn in his side, said on Twitter: "I denounce this arbitrariness to the national and international community."
She did not say where she was on Saturday.
"An aggression against her is an aggression against Venezuelan democracy," the head of the Organization of American States (OAS), Luis Almagro, tweeted.
On Friday, the OAS' Inter-American Commission on Human Rights ordered Venezuela to protect Ortega, saying her life was at risk after she launched an investigation into the legality of the new, all-powerful Constituent Assembly.
Venezuela's government perceives the commission to be under US influence and brushes off its pronouncements.
Maduro's former foreign minister Delcy Rodriguez, who now heads the assembly beginning operation on Saturday, has vowed to immediately go after those deemed to be obstructing government policies.
And Maduro said ominously on Friday that "if we had an attorney general here that acted... all these violent protesters would already be in jail."
The United States, the European Union, the Vatican and major Latin American nations including Mexico, Argentina and Chile have all rejected the assembly.
The opposition, which controls the legislature now effectively sidelined, has said the body is a step towards a Maduro "dictatorship."
The Constituent Assembly was elected a week ago in polls marred by violence and allegations of fraud.
A British-based firm that supplied the voting technology, Smartmatic, said the turnout figure was "tampered with" and greatly exaggerated.
Subsequent US sanctions directly targeting Maduro and more were threatened against the assembly's 545 members.
On Saturday, a South American trading bloc, Mercosur, was meeting in Brazil to decide whether to suspend Venezuela from the organization.
Maduro has responded by lashing out at US "imperialism" and calling the heads of other Latin American states vassals to Washington.
Rodriguez said on Friday: "The international community should not make a mistake over Venezuela. The message is clear, very clear: we Venezuelans will resolve our conflict, our crisis without any form of foreign interference."
The principal task of the Constituent Assembly is to rewrite the constitution. But while working on that, it enjoys supreme powers over all other branches of government.
On Friday, the body took over an ornate chamber under a golden dome in the Legislative Palace in Caracas -- at the far end of a building shared with the opposition-run legislature, the National Assembly.
All its members are Maduro allies, and their number includes the president's wife and son.
The opposition has vowed to maintain street protests against the assembly, but the risk has grown that the new body could take sterner measures against demonstrators.
The Vatican has already urged Venezuela's security forces to show restraint after a death toll of 125 from four months of unrest.
The new assembly is a pillar for Maduro to maintain authority. He has no more than 20 percent public support, according to surveys by the Datanalisis polling firm, and increasingly relies on backing from the military and judicial and electoral authorities.
Although the president has vowed that the assembly would solve Venezuela's crippling economic and political crisis, there was scepticism on the streets.
Food, essentials and medicine are scarce, the decline of the currency is accelerating, inflation is in triple digits, reserves to pay sovereign debt are dwindling, and thousands of Venezuelans are leaving to seek survival in neighbouring countries.
Maduro has dismissed the problems as part of an "economic war" waged against him by the opposition in collaboration with the United States.
His main sources of support from abroad are Cuba, whose socialist model he admires, and Russia, which holds billions in Venezuelan debt.