Troops in Venezuela put down a "terrorist" attack on an army base in the country's third city of Valencia on Sunday, military chiefs said, after a video surfaced of uniformed men declaring an army "rebellion" there.
Several of the assailants were arrested, officials said, after reports of shots being fired near the base in the city's Paramacay Fort used by the National Bolivarian Armed Forces (FANB in Spanish).
"Our FANB successfully repelled a paramilitary criminal terrorist attack, the 7 captured are giving information!" Rear Admiral Remigio Ceballos, head of the military's strategic operational command, said on Twitter.
The head of the armed forces, Defense Minister Vladimir Padrino, tweeted: "They couldn't do anything against the FANB... they try to assault it with terrorist attacks. They can't."
Local media and social networks spoke of a possible military uprising in the city against the government of President Nicolas Maduro, but there was no immediate confirmation.
In the video posted online, a man presenting himself as an army captain declared a "legitimate rebellion... to reject the murderous tyranny of Nicolas Maduro."
Speaking with 15 other men dressed in camouflage standing by him, some of them armed, he demanded a transitional government and "free elections."
The deputy leader of Maduro's Socialist Party, Diosdado Cabello, was the first official to tweet news of the attack.
He said troops had been deployed in its wake "to ensure domestic security" and there was "absolute normality in the other military units in the country."
The reported unrest occurred as a new assembly with supreme powers and loyal to Maduro started functioning in Venezuela, a week after it was elected in polls marred by violence and allegations of vote-tampering.
On Sunday, the assembly announced the creation of a "truth commission" to probe alleged crimes committed during Venezuela's lengthy political crisis.
The opposition and dozens of foreign governments say the new body is illegitimate and serves only to support a Maduro "dictatorship" by bypassing the opposition-controlled legislature.
In its first act on Saturday, the body, the Constituent Assembly, ordered the dismissal of the country's attorney general, Luisa Ortega, who became a vociferous critic after breaking ranks with Maduro.
Ortega's dismissal triggered an international outcry, and she has refused to recognize it.
The United States, which has imposed sanctions on Maduro, called the sacking "illegal," with a State Department spokeswoman saying it was aimed at tightening the "authoritarian dictatorship of (the) Maduro regime."
Colombia, Chile, Guatemala, Mexico, Panama and Peru also slammed the decision.
At the same time, Argentina, Uruguay, Paraguay and Brazil announced Venezuela's indefinite suspension from the South American trading bloc Mercosur for its "rupture of the democratic order."
"The countries of the region... must continue to tell the Venezuelan regime that in the Americas, there is no place for dictatorships or for the tyrants that lead them," the secretariat of the Organization of American States (OAS) said in a statement.
Also on Saturday, an opposition leader, Leopoldo Lopez, was returned to house arrest after being detained in military prison for four days.
Lopez had been arrested along with another opposition leader, Antonio Ledezma -- who was released back to home detention Friday -- in the aftermath of the highly contested vote to create the assembly.
Maduro and his Socialist Party have "completely taken hostage" Venezuela's institutions through "an undemocratic mechanism that is utterly dictatorial," the leader of the opposition-controlled legislature, Julio Borges, told reporters.
The opposition has vowed to maintain street protests against the assembly.
Four months of demonstrations violently quelled by security forces have left at least 125 people dead.
But the rallies grew more muted this week as the assembly vowed to go after those seen as inciting street action.
Maduro responded to the international criticism by telling an Argentine radio station that "Venezuela will not be taken out of Mercosur -- never!"
He accused his Argentine counterpart, Mauricio Macri, of trying to impose a "blockade" on Venezuela and US President Donald Trump of wanting to grab the country's vast oil reserves.
Maduro has around 20 percent public support, according to surveys by the Datanalisis polling firm.
Ordinary Venezuelans are struggling, with food, essentials and medicine scarce, the currency rapidly depreciating, and inflation soaring. Thousands have sought shelter in neighboring countries, particularly Colombia and Brazil.