Hundreds of opposition protesters marched in Caracas on Sunday, chanting "we want the truth" as they called on the government to give more details about the health of cancer-stricken President Hugo Chavez.
Waving Venezuelan flags, the protesters rallied to a street where some 50 university students have staged a week-long sit-in to demand more transparency about Chavez's condition.
"We want to know what is going with Chavez's health, if he is alive or dead, and we want elections," said Dario Alberici, 55, an public accountant who was blowing on a plastic trumpet in the yellow, red and blue colors of Venezuela.
Pro-government protesters held their own rally in support of Chavez in another part of the capital.
Vice President Nicolas Maduro revealed Friday that the leftist leader is undergoing chemotherapy in a Caracas military hospital, but he says Chavez remains in charge.
In power for 14 years, the once omnipresent president has not emerged in public since undergoing cancer surgery in Cuba on December 11.
Chavez was first diagnosed with cancer in the pelvic region in June 2011, but the government has never disclosed its exact nature, severity or location.
"Nobody knows where he is," said Hector Gonzalez, a 70-year-old engineer. "If he is recovering, they should show him. The country cannot continue in this uncertainty."