Venezuela military chief backs Maduro, calls protests "coup in progress"

Venezuela's military chief claimed Tuesday that the country was facing a coup , as new protests were expected following President Nicolás Maduro's disputed victory in the weekend's election. The country's opposition leaders say they won the vote by a significant margin, and a local NGO has reported at least six people killed in unrest that has followed the official declaration of Maduro's win.

Venezuela's attorney general Tarek William Saab said 749 people had been arrested amid the protests, and he warned that number could rise in the coming hours, according to the AFP news agency.

Most would be charged with "resisting authority and, in the most serious cases, terrorism," Saab said.

Election officials in the tightly controlled Latin American nation declared Maduro the winner , granting him a third six-year term after the weekend election, despite exit polls that showed him losing by a significant margin, according to challenger Edmundo González and opposition leader María Corina Machado, who have claimed to have proof that Gonzalez received over twice the votes Maduro did.

"I speak to you with the calmness of the truth," González said Monday outside his campaign headquarters in Caracas, The AP reported. "We have in our hands the tally sheets that demonstrate our categorical and mathematically irreversible victory."

The opposition leaders invited supporters to gather peacefully on Tuesday and urged people to remain calm. In a social media post, González called on the nation's security forces to "respect the will of the people voiced on July 28 and to halt the repression of peaceful demonstrations."

But declaring the military's backing for Maduro, Defense Minister General Vladimir Padrino denounced the protests, saying on state TV: "There is a coup in progress so President Nicolás Maduro has stepped up to stop it again, and with him the people who elected him president, all the institutions, the Bolivarian armed forces and the democratic institutions."

"We will defeat the coup," Padrino said.

International criticism of Maduro was growing on Tuesday.

"The worst form of repression, the most vile, is to prevent the people from finding solutions through elections," the Organization of American States said in a statement criticizing the National Electoral Council, which is loyal to the ruling party, for its delay in showing precinct-level results.

"The obligation of each institution in Venezuela should be to ensure freedom, justice, and transparency in the electoral process. The people should have the maximum guarantees of political freedom to be able to express themselves at the polls, and to protect the rights of citizens to be elected," the statement said.

The organization suggested a potential do-over election with a robust international observer mission, and it called an urgent meeting of its members.

Maduro took office in 2013, and during his presidency, more than seven million Venezuelan citizens have fled the country, which has been mired in poverty and violence. Many have gone to the U.S.-Mexico border and attempted to cross into the U.S.

"What Venezuelan is going to brave the jungle? They kill you. They take your money. They rape you. What woman, what person, what human being is going to brave this without it being a necessity?" Blanca Sanchez, who fled the country with her young boys and returned just to vote, hoping to help bring about a change of government, told CBS News in Caracas.