CARACAS, Venezuela -- Thousands of Venezuelans held separate protests Saturday to support and condemn an opposition-aligned TV station that President Hugo Chavez's government has threatened with closure.

Opposition protesters marched to Venezuela's journalists' association, chanting "Journalism is freedom!" Some waved Venezuelan flags, while others carried signs reading: "They won't shut us up."

In recent weeks, the government has stepped up its confrontation with Globovision -- the only strongly anti-Chavez channel remaining on the open airwaves. Earlier this month, the president urged Globovision's executives to reflect on the station's tough criticism of his government or face shutdown.

With public prompting from Chavez, prosecutors and regulators have recently taken a range of actions against Globovision.

Venezuela's telecommunications regulator has opened four separate investigations into the station for presumed violations -- most recently, asking prosecutors to determine if the channel is responsible for a talk show guest's suggestion that foes might kill Chavez. The probe could potentially force Globovision off the air.

Venezuela's tax agency, meanwhile, has ordered the station to pay a total of $4.2 million for back taxes that allegedly went undeclared in 2002 and 2003 plus a fine.

Mary Pojah, a 73-year-old retired teacher, said she believes Globovision's closure would be "terrible for Venezuela."

"It's the only channel that keeps us informed," she said. "People without freedom of expression are not free."

Ana Mercedes Becerra, a 55-year-old therapist, wore a red gag over her mouth in protest. "We can't express what we feel without facing prejudice from this government that doesn't accept criticism," she said.

Thousands of Chavez supporters, meanwhile, marched separately to Venezuela's National Assembly in a show of support for the government's actions.

Information Minister Blanca Eekhout said the nation has "suffered the consequences of a media dictatorship."

"The power must be taken from the great transnational media outlets and given to the people," Eekhout told Union Radio.

Chavez faults Globovision and other private channels for supporting a short-lived 2002 coup against his government. Two other channels have since toned down their opposition, while the government refused to renew the concession for a third anti-government station, RCTV, in 2007. RCTV has since moved to cable.

National Assembly president Cilia Flores told pro-Chavez marchers that "concerning communication laws, the public and national debate is open."

"We will tackle not only the laws, but also the role of media" in society, she said.