Caracas (AFP) - Venezuela's military was on Monday hunting an ex-officer and a lieutenant who led uniformed rebels on a weekend raid to grab weapons from an army base, fueling fears the country's worsening crisis could tip into armed conflict.

The defense minister and head of the armed forces, General Vladimir Padrino, said the ex-National Guard captain, Juan Carlos Caguaripano, and the lieutenant, Jefferson Gabriel Garcia, were behind Sunday's attack on the base in the northwestern city of Valencia by 20 men in uniform.

They are "enemies of the nation," Padrino said.

Just before the raid, Caguaripano posted a video online declaring it part of a "legitimate rebellion... to reject the murderous tyranny of (President) Nicolas Maduro."

Appearing with more than a dozen uniformed men, some armed, he demanded a transitional government and "free elections."

Maduro said on state television Sunday that the attack saw a three-hour firefight in which two of the rebels died and eight were captured, including another lieutenant who was involved.

Ten other attackers made off with an unspecified arsenal.

Caguaripano and Garcia "managed to flee and a special operation has been deployed to find and capture them" and recover the weapons, Padrino said.

He said Garcia had been in charge of the base's weapons depot and acted as an accomplice from the inside, while Caguaripano had been discharged from the army in 2014 after multiple disciplinary offenses.

Padrino said most of the rebels were civilians with criminal records, contracted in Venezuela by people with links to pro-opposition sympathizers in Colombia and the United States.

He and Maduro described the attackers as "terrorists" and "mercenaries" and insisted they did not signify any fracturing of the army.

"This group was not acting for ideals or nationalist principles. They were paid from Miami by extreme-right groups linked to the Venezuelan opposition as well as foreign governments that maintain a hostile and interfering attitude against the country," Padrino said.

Story continues

- Loyal brass -

The defense minister insisted the military's loyalty to Maduro's government -- a third of which is controlled by current or former officers -- was unshakable.

Questions were being asked, however, whether lower ranks in Venezuela's military could rebel.

The opposition coalition, the Democratic Unity Roundtable, said the country's crisis dividing Venezuela's society "is being seen... in the barracks of our armed forces."

The head of the opposition-controlled congress, Julio Borges, has demanded the "truth" from the government about what happened on Sunday.

Analysts said discord could be seen in the lower ranks of the security forces.

"There are indications of growing discontent in the middle ranks of the police and soldiers, even though military commanders remain allied to the government," said Diego Moya-Ocampos, of IHS Markit Country Risk in London.

"You can expect new incidents to occur as this unease grows," he said.

On Monday, hackers calling themselves The Binary Guardians hijacked the home pages of several government bodies and private companies in support of the rebel raid. In several websites, they posted excerpts from Charlie Chaplin's movie "The Great Dictator."

- Venezuela isolated -

Venezuela's opposition has repeatedly urged the military to abandon Maduro, so far to no avail.

The crisis in the oil-rich country is rooted in large part in the collapse of its economy due to a plunge in global oil prices. Public anger is spreading as people struggle for basics like food and medicine.

Maduro, however, blames an economic "war" that he says is fomented by the right-wing opposition in cahoots with the United States.

Venezuela has become increasingly isolated internationally as Maduro tightens his hold on power through a contested loyalist assembly that started work last week.

Opposition leaders are under increased threat of arrest after protests -- fiercely countered by security forces -- left 125 people dead in the past four months.

The new "Constituent Assembly" has moved quickly to clamp down on dissent. Its first act was to dismiss the attorney general, Luisa Ortega, who had broken ranks with Maduro to become one of his most vociferous critics.

It has also created a "truth commission" that Maduro wants to use to prosecute opposition lawmakers and leaders for alleged "crimes."

Then, lawmakers in the opposition-controlled legislature said late Monday their chamber was stormed by officials from the rival assembly loyal to Maduro with the backing of soldiers.

The legislature posted photos on its Twitter account of a group of people in the chamber it uses in the Legislative Palace in Caracas.

The people who invaded its chamber, it said, included the leader of the Constituent Assembly, Maduro's former foreign minister Delcy Rodriguez.

The United States accuses Maduro of installing an "authoritarian dictatorship" that has turned Venezuela into an international pariah.

The United States, Brazil, Colombia, Chile, Guatemala, Mexico, Panama and Peru have slammed the "illegal" sacking of Ortega.

Foreign ministers from across Latin America were to meet in Peru on Tuesday to decide what joint action they could take over Venezuela.