Venezuelan opposition leaders Leopoldo Lopez and Antonio Ledezma have been taken from their homes, where they were serving house arrest, family members said on Tuesday, adding that President Nicolas Maduro was responsible for their fates.
Both leaders in recent days have called on Venezuelans to join protests against Maduro over the creation of an all-powerful legislative body called the constituent assembly, which was elected on Sunday.
The vote for the assembly was boycotted by the opposition and has been criticized around the world as an assault on democratic freedoms.
"12:27 in the morning: the moment when the dictatorship kidnaps Leopoldo at my house," Lopez's wife Lilian Tintori wrote on Twitter.
She included a link to a video of what appears to be Lopez being led into a vehicle emblazoned with the word Sebin, Venezuela's intelligence agency.
Vanessa Ledezma posted a similar video of Ledezma.
The Information Ministry did not immediately respond to an email seeking comment.
Lopez was granted house arrest in July following three years in prison for his role in anti-government street protests in 2014. His release was considered a major breakthrough in the country's political standoff.
Lopez's lawyer, Juan Gutierrez, wrote on Twitter that "there is no legal justification to revoke the house arrest measure."
Ledezma was granted house arrest in 2015 after being imprisoned on charges of leading a coup against Maduro.