Venezuelan Journalists demonstrate Monday in front of the national telecommunications center in Caracas. Venezuelan regulators revoked the broadcast rights of 34 radio stations on Friday, deepening a rift between Venezuelan President Hugo Chavez’s government and the private media.

Caracas, Venezuela ? Radio hosts hung their heads as their FM station was forced off the airwaves along with 33 other broadcasters targeted by President Hugo Chavez’s government in what critics say is a campaign to muzzle his foes.

For the first time in decades, CNB 102.3 FM fell silent over the weekend after Venezuela’s telecommunications regulators revoked some of the 34 stations’ licenses and refused to renew others.

But CNB challenged the government action within hours by starting to transmit programming over the Internet. Sportscaster Juan Carlos Rutilo told his online listeners: “Today freedom of expression is being restricted. … Today you have one less option.”

Media groups and human rights activists note more than 200 other stations are under investigation for allegedly not being properly licensed and accuse Venezuela’s leftist leader of pursuing a widening crackdown to silence dissent.

In a similar step, one of Chavez’s leftist allies, Ecuadorean President Rafael Correa, announced Monday that “many” radio and TV frequencies will revert to the state over what he called irregularities in their licenses. He gave no specifics.

A majority of the stations affected in Venezuela aired criticisms of the government, though they were not overtly anti-Chavez and much of their programming ranged from American rock to salsa and traditional Venezuelan music.

In the country’s polarized media landscape, CNB took a relatively balanced approach by interviewing pro-Chavez lawmakers while also having opposition politicians among its talk show hosts.

Venezuela still has many private radio stations and newspapers that take a hard line against Chavez and strongly criticize the government through both news reports and commentary. But in the last decade, the government has built a growing coalition of state-run media outlets, and some TV channels once virulently anti-Chavez have toned down their criticism.

The only stridently anti-Chavez television channel that remains on the open airwaves, Globovision, is facing multiple investigations that could force it off the air.

Tensions ran high at Globovision’s studios Monday as government supporters, riding motorcycles and waving the flags of a radical pro-Chavez party, tossed tear gas canisters at the station.

The channel said one guard suffered a burned hand when he tried to pick up one of the canisters, and a police officer posted outside was hit in the head by a hurled object and required stitches. Globovision broadcast video showing clouds of tear gas outside the building as employees ran for cover. Two workers were treated after inhaling tear gas.

Globovision’s director, Alberto Federico Ravell, condemned the violence and urged Chavez to control his backers. He said some of some of the armed assailants threatened security guards.

Justice Minister Tareck El Aissami condemned “this violent action against a television channel” and said authorities were investigating.