At least 46 people have been killed in the worst turmoil faced by Maduro since he won the presidency in 2013. Venezuelans from civilians to police have been killed, sometimes during increasingly frequent spates of looting or street melees.

Many Venezuelans are furious with Maduro's government, blaming it for soaring inflation, shortages of everything from food to medicine, and a crackdown on human rights. They are demanding elections, freedom for jailed activists, foreign aid, and autonomy for the opposition-led legislature.

Major opposition marches took place across the oil-rich nation of 30 million on Saturday, with protesters in Caracas brandishing placards that read "No More dictatorship in Venezuela" while in the volatile border city of San Cristobal masked youths threw rocks, and a Reuters witness saw two protesters wielding machetes.

The Andean area near Colombia suffered a week of mayhem that included looting, prompting the government to send in 2,000 troops.

"We don't want more deaths. We want salaries that mean something, and medicines. The government invests more in bullets and weapons than in food and education for this country," said Maria Diaz, a 33-year-old lawyer standing in the torrential rain in front of security forces with some 8,000 other protesters in San Cristobal.