By JUAN FORERO
 
BOGOTÁ, Colombia, Dec. 8 - President Hugo Chávez of Venezuela signed a new law on Wednesday that would permit the government to censor news reports.

Advocates of press freedom said the measure was aimed at silencing the most defiant critics of Venezuela's leftist government.

The new law, vaguely worded and open to wide interpretation, prohibits scenes of violence and sex during daylight hours, which government officials say is necessary to shield children from harmful broadcast programming. But that provision, critics say, would allow the government to ban news reports of violent protests or government crackdowns.

The law, which outlines 78 possible infractions, also stipulates that the news media cannot put out reports that endanger national security or incite disruption of public order.

"This law is so vaguely defined, with so many clauses and so broad, that it is like a loose-fitting strait-jacket on a patient, one that can be easily tightened when necessary," José Miguel Vivanco, director of the Americas division of Human Rights Watch, said by phone from Washington.

The law details rules governing violence, sex and lewd language in programming, measures that Teodoro Petkoff, a newspaper editor and political analyst, says would normally lead to few objections. Infractions are punishable with fines.

But Article 29 of the 35-article piece of legislation, Mr. Petkoff says, is "venomous," permitting suspension of a broadcaster's license for a range of broadly defined violations.

"It is sufficiently vague, sufficiently broad, so that anything fits in there," said Mr. Petkoff, a former leftist guerrilla who edits Tal Cual, an irreverent Caracas daily. "This is a dangerous article."

The government, however, insists that the law is necessary to tame fiercely anti-Chávez broadcast stations whose owners and managers form a radical wing of a coalition of antigovernment groups that has tried to oust the president through a coup and four economically devastating national strikes.

The private media in Caracas blacked out coverage of the uprising that reinstalled Mr. Chávez in power two days after his overthrow in 2002, in an effort intended to save the interim government of Pedro Carmona that briefly took power. And after Mr. Chávez won a recall referendum, which his opponents engineered last August, the press maintained for weeks that he had won through fraud even as the charge appeared increasingly baseless after international monitors declared the result legitimate

Faked reports damaging to the government are not unusual, and typical programming usually features long lines of antigovernment leaders, rarely impartial observers.

"This law is now beginning to liberate the people of Venezuela from the dictatorship of the private media owners," the president said Tuesday in a fiery speech.