Venezuela's controversial "Constituent Assembly," a new legislative body with supreme powers packed with supporters of President Maduro, began its first session in Caracas on Friday.
The assembly of 500-plus members, which is tasked with rewriting the crisis-wracked country's constitution, took its seats in an oval chamber under the golden dome of the capital's 145-year-old Legislative Palace.
Veteran loyalist politician Fernando Soto formally announced the opening of the session.
He was followed by a priest endorsing the body -- despite a statement from the Vatican earlier Friday that the assembly had added to a "climate of tension" in the country.
The assembly's members were accompanied to the palace by Maduro and thousands of supporters carrying the national flag and portraits of late president Hugo Chavez.
"The people today are going back to the assembly building and will never leave," said one supporter, 72-year-old Euclides Vivas.
The opposition-controlled legislature, the National Assembly, has vowed to keep sitting in a different chamber in the Legislative Palace.
It has denounced the new body, which was elected last weekend, as "fraudulent."
That claim was apparently backed by a British-based company involved in the vote, Smartmatic, which said the official turnout figure had been "tampered with" and exaggerated.
The United States, the European Union and major Latin American nations including Argentina, Colombia and Mexico have all said they will not recognize the Constituent Assembly.
The United States imposed direct sanctions on Maduro over its election and warned the assembly's members could also be targeted by punitive measures.