Venezuela released two prominent government critics from prison this week, including a former defense minister who had been a confidant of President Hugo Chávez.
The former defense minister, Raúl Baduel, had spent more than six years in a military prison serving a sentence on corruption charges that he said were retaliation for his breaking ranks with Mr. Chávez. Mr. Baduel was given parole, but with restrictions that included a ban on speaking to the news media, according to local news reports.
The other prisoner, Daniel Ceballos, a former mayor of San Cristóbal, was released to house arrest on Tuesday for what officials said were medical reasons.
Mr. Ceballos was convicted and completed a sentence for failing to halt antigovernment protests last year in his city, an opposition bastion in western Venezuela. But he had remained in prison while the government said it was preparing further charges against him.
It was not clear if the unexpected releases represented a significant shift in the fiercely antagonistic relationship between the opposition and the government of President Nicolás Maduro, the protégé and successor of Mr. Chávez, who died in 2013.
Photo
The former mayor of San Cristóbal, Daniel Ceballos, center, looked out from his Caracas apartment with his family on Wednesday. Mr. Ceballos, who had been held on charges related to widespread antigovernment protests last year, was released to house arrest.CreditAriana Cubillos/Associated Press 
They came as the government has been deploying a variety of tactics that appear aimed at weakening or dividing the opposition ahead of legislative elections scheduled for December. The government has declared several politicians and activists, such as Mr. Ceballos, ineligible to hold public office and has used court orders to mandate changes in the leadership of some political parties.
Several other dissidents remain imprisoned. The most prominent among them is Leopoldo López, a politician who is being tried on charges of inciting violence during the antigovernment protests, which began in early 2013. He has spent more than a year in the same military prison where Mr. Baduel was held.
Another is Mr. Baduel’s son, Raúl Emilio Baduel, who was arrested during last year’s protests.
Both Mr. López and the younger Mr. Baduel are among the politicians and activists who were declared ineligible to hold public office.
Another jailed opposition leader, Antonio Ledezma, the mayor of Caracas, was released to house arrest for medical reasons in April. He was arrested in February after officials said that he was involved in a plot to overthrow the government.
Mr. Ledezma’s detention drew strong international condemnation but the pressure on the government eased after he was moved to house arrest.
“In these cases of house arrest, like Antonio Ledezma and Daniel Ceballos and others, it appears that the objective of the government is to lower the political profile of these people, because generally when someone is in prison they have a very high profile and get a lot of attention in the media and social networks,” said José Vicente Haro, a lawyer who has worked on many cases of imprisoned dissidents.
The older Mr. Baduel was once one of Mr. Chávez’s closest collaborators, and he led a mission to free Mr. Chávez after he was briefly removed as president during a coup attempt in 2002.
But Mr. Baduel, a former general, quit his post as defense minister in 2007 and publicly criticized Mr. Chávez for seeking constitutional changes that would expand his power. He was arrested in 2009 and was later sentenced to nearly eight years in prison.
Mr. Maduro has been under international pressure to release imprisoned dissidents. The issue was raised in meetings this year between a United States envoy, Thomas A. Shannon Jr., and Mr. Maduro and other top officials, according to a senior State Department official.