CARACAS, Venezuela - Venezuelan lawmakers on Monday imposed broadcast-type regulations on the Internet, barring some types of online messages under measures that opponents say are a threat to free speech.

President Hugo Chavez's allies in the National Assembly approved the revised Social Responsibility Law, which extends rules for broadcast media to the Internet.

The law bans messages and images that "disrespect public authorities," "incite or promote hatred" or crimes, or that could create "anxiety in the citizenry or alter public order."

It also says electronic media must establish procedures to "allow the restricting, without delay" of content deemed objectionable. Violators may be punished with fines.

Chavez opponents and media-freedom groups have strongly criticized the law, saying it is another in a line of legal changes that they fear could be used to clamp down on freedoms. Questions remain about how the measures would be enforced.

Chavez defended the law, saying it was intended to help protect people against online crimes.

"We aren't eliminating the Internet here . . . nor censoring the Internet," Chavez said. "What we're doing is protecting ourselves against crimes, cybercrimes."

As examples, Chavez mentioned messages promoting drug use, prostitution, and other crimes, and said his government had an obligation to take a stand.

Pro-Chavez lawmaker Mario Isea said the law - which will take effect once published in the Official Gazette - would not restrict Internet use. But opposition lawmaker Pastora Medina argued it was intended to "restrict, censor," and also promote self-censorship.

The Venezuelan Electronic Commerce Chamber condemned the measures in a recent statement, saying they aimed to clear the way for "censorship and blocking of websites."

The law is one of a number of controversial measures taken up by the National Assembly in its final weeks before a new legislature takes office in January with a larger opposition contingent capable of hindering some types of major laws.

Venezuelan authorities have prosecuted some people for remarks made online, in some cases alarming free-speech advocates. A man employed by Venezuela's state electric utility was arrested in September after authorities said he used Twitter to call for Chavez's assassination.

Jesus Majano was arraigned and then freed pending additional hearings. Prosecutors have accused him of "instigating public hatred."

In July, prosecutors accused two people of spreading false rumors about the country's banking system on Twitter. The Attorney General's Office said the two were detained and then freed, also pending additional hearings.

The media-freedom group Reporters Without Borders accused the government of targeting people for expressing their views online.