"They've just taken Leopoldo from the house," Lilian Tintori wrote on Twitter. "We don't know where he is or where they're taking him."

The wife of opposition leader Leopoldo Lopez posted what appeared to be video of him being taken from their home after midnight.

It is President Nicolas Maduro's first moves against his enemies since a widely denounced vote giving his government nearly unlimited powers.

"They've just taken Leopoldo from the house," Lilian Tintori wrote on Twitter. "We don't know where he is or where they're taking him."

Allies of former Caracas Mayor Antonio Ledezma posted video online of a man who appeared to be the opposition leader being taken by state security as a woman screams for help for neighbors.

"They're taking Ledezma!" she cries. "It's a dictatorship!"

Lopez was detained three years ago after protests against Maduro's government and sentenced to more than a decade in prison on charges that include inciting protesters to violence. 

He was released last month to serve the rest of his term under house arrest. Ledezma, a former Caracas mayor, was also detained in 2015 and has been under house arrest.