Mexico City, Mexico - Mexico's governing party appeared to step away on Wednesday from a proposal that would authorize officials to block Internet and telecom signals, pulling back a day after anti-censorship protests that ended in clashes in Mexico City.

Senator Emilio Gamboa, leader of the ruling Institutional Revolutionary Party in the Senate, said proposed communications legislation would be changed to avoid a distracting debate over issues that he said were never central to the proposal.

A draft of the bill that his party supports in the Senate has provisions permitting authorities to "temporarily block, inhibit, or annul telecommunications signals at events and places deemed critical for the public safety."

Gamboa promised such clauses would be deleted. At present, authorities block cellphone signals in some sensitive areas, like prisons, but the proposed bill appeared to vastly widen that power.

"Any other additional power ... like the blocking of signals for national or public safety will be excluded from the reform," Gamboa said at a news conference.

Gamboa said the bill's rather broad language requiring telecom providers to provide data on users would be limited to measures already in effect to permit authorities to locate a user and obtain telephone records for criminal investigations in cases like kidnappings.

The bill's Internet-blocking provisions sparked a march by hundreds of protesters through downtown Mexico City on Tuesday.

Protesters carrying signs that read "No to Censorship" and "Freedom of Expression" walked along Reforma avenue toward the Senate building in a demonstration organized on social networks. While most of the march was peaceful, the Mexico City Human Rights Commission said police pushed and grappled with some protesters near a television network office and manhandled the governmental commission's own inspectors.

Raul Trejo, an expert on media at the National Autonomous University of Mexico, said the Mexican government's attempt to block Internet and telecom signals "is part of an international tendency."

"A lot of governments are showing an interest in blocking signals," Trejo said. "All governments are uncomfortable with the Internet."

The bill before the Senate is an enabling law for the constitutional reforms enacted last year aimed at decreasing the power of a few powerful companies that control Mexican phone, Internet, and television services. The changes are meant to increase competition and access in telecommunications, and included creation of a powerful, independent government watchdog agency to enforce the rules.

Mexico's powerful media and telecom companies have been fighting to bend the reforms in their own interest, running full-page newspaper ads lobbying against their competitors' supposed advantages under the law.

That effort may have had an effect. Trejo worries the enabling legislation weakens some of the provisions contained in last year's overhaul, for example, by transferring some powers from the watchdog agency to the Interior Department, long considered the president's political operations agency.

"If the enabling legislation is approved the way it is right now, it's going to go against the Constitution, it's not going to work," Trejo said.