Supporters of Venezuela's Chavez and his reforms stage massive march

Tens of thousands of Venezuelans marched through the capital on Sunday, in a show of support for changing the constitution to greatly expand socialist President Hugo Chavez's power and allow him to run for re-election indefinitely.

Waving flags and wearing the red of Chavez's ruling party, the "Chavistas" — as the president's backers are known — shouted slogans in favor of the 69 proposed amendments in a procession that stretched for several kilometers (miles).

Vice President Jorge Rodriguez predicted a solid victory in a Dec. 2 up-down referendum on the changes, which were overwhelmingly approved Friday by the Chavista-controlled National Assembly.

"This swarm of people is absolutely convinced the constitutional reforms must be approved," Rodriguez said.

Chavez, who won re-election last year on promises to transform Venezuela into a socialist state, says the changes would expand democracy by giving neighborhood-based assemblies administrative responsibilities usually reserved for elected officials.

But human rights groups, the Roman Catholic Church and other critics accuse Chavez of trying to consolidate power in his presidency, pointing to the proposed elimination of presidential term limits and other amendments.

Opposition leaders also warn that changes allowing authorities to detain citizens without charge and censor the media during a state of emergency would violate civil liberties.

After marching through the city, the demonstrators jammed a downtown avenue where they listened to Venezuelan folk music booming from loudspeakers and raised banners bearing images of Cuban leader Fidel Castro and famed revolutionary fighter Ernesto "Che" Guevara.

Venezuela — a major supplier of oil to the United States — is deeply divided over Chavez's rule, with government opponents fearing an impending dictatorship. But a weak opposition has repeatedly failed to derail the president's political initiatives at the ballot box.

Thousands of people demonstrated against the amendments in rallies Friday and Saturday. Two people were killed and four injured by a gunman during student-led protests outside a university in western Zulia state.