The battle for Venezuela is being fought as vigorously online as in the streets.
Authorities have cut off the Internet to San Cristobal, a clash-torn university city, and have blocked selected websites as well as Zello, a "walkie-talkie" service widely used by protesters.
San Cristobal, home to several universities, is where the current wave of anti-government demonstrations began.
On Thursday, the U.S. company Zello told The Associated Press that Venezuela's state-run telecoms company, CANTV, had just blocked access to the push-to-talk "walkie-talkie" app for smart phones and computers that is used by protesters around the world, including Ukraine.
Zello reported more than 150,000 downloads in Venezuela on one day this week.
Activists reported a serious degradation in the Internet service provided by CANTV, which handles about 90 percent of Venezuela's traffic.
President Nicolas Maduro had ordered NTN24 removed from air last week after it broadcast a video of a student killed by a gunshot to the head.
Renesys, a U.S.-based top analyzer of global Internet traffic, confirmed the website blocking and service degradation, but said it could not determine if CANTV was decreasing bandwidth.
Venezuela's traffic to Cuba over the ALBA-1 undersea cable appeared unaffected,according to Renesys' Doug Madory.
Government officials have not commented on the Internet outage, nor on the service degradation and website blocking.
Nearly half Venezuela's population relies on government-controlled media as its sole information source and the rest is onhrough the Internet.
But cutting off the Internet is not smart political strategy, according to Danny O'Brien, international director of the Electronic Frontier Foundation.
"I think the important lesson people should learn from these Internet blackouts is that they just throw fuel on the flames of civil unrest," he said.
--Reporting by the Associated Press