CARACAS, May 3 (Reuters) - Venezuelan opposition supporters gathered on Wednesday to march down Caracas' main thoroughfare to protest leftist President Nicolas Maduro's creation of a powerful assembly, which it views as a ruse to dodge free elections so he can remain in office.
Building on over a month of large and sustained protests, opposition leaders have vowed more street action after Maduro's announcement on Monday that he was creating a "constituent assembly" empowered to rewrite the constitution.
The government says protest-related violence and the opposition's unwillingness to hold talks with officials left Maduro with no choice but shake up Venezuela's governing apparatus.
The opposition wants to bring forward the 2018 presidential vote amid a devastating economic crisis. It says Maduro's announcement is a cynical ploy to confuse citizens into thinking he has made concessions when in fact he is seeking to tweak the system to avoid elections the Socialist Party would likely lose.
"This constituent assembly seeks to impose a Cuban electoral model," said opposition lawmaker Jorge Millan.
"We Venezuelans are not going to allow fraud," he added.
Wednesday's march was planned for the Francisco Fajardo highway, the city's main thoroughfare. Running through Caracas' main valley, it links the eastern, central and western parts of the city.
Maduro's move has drawn condemnation from the United States and some Latin American countries, including regional powerhouse Brazil that labeled it a "coup."
An influential group of U.S. senators will file sweeping legislation later on Wednesday to address the crisis in Venezuela, including sanctioning individuals responsible for undermining democracy or involved in corruption, Reuters reported.
But Maduro has received backing from regional leftist allies including Cuba. Bolivia's President Evo Morales said Venezuela had the right to "decide its future... without external intervention."
Maduro was to meet later on Wednesday with election officials, where more details of the process were expected. Maduro has already said the 500 members of the constituent assembly would be elected by social groups including workers, indigenous people, and farmers, as well as on a municipal level.
At least 33 people have been killed, more than 400 people injured and over 1,000 arrested since the anti-Maduro unrest began in early April. There were four additional deaths on Tuesday, officials said.
Two people died when a vehicle tried to avoid a protester barricade in the state of Carabobo, Venezuela's Civil Protection agency tweeted late on Tuesday.
Angel Moreira, 28, who was on a motorbike on a highway leading out of Caracas, also died after a vehicle ran him over while trying to avoid a demonstration, the state prosecutor's office said on Wednesday.
In addition, the office said Yonathan Quintero, 21, had been killed while a group was "damaging" a business after a protest in the Carabobo state capital of Valencia.
The opposition says heavy-handed security forces and armed government supporters are trying to scare protesters from taking to the streets in violent Venezuela, awash with guns and home to one of the world's highest murder rates.
Maduro, a former bus driver and union leader elected to replace the late Hugo Chavez in 2013, retorts thuggish protesters are fanning violence and vandalism.
Typically at protests, thousands rally peacefully but are then blocked from marching, often with teargas, to government buildings. At that point, masked youths appear throwing stones and Molotov cocktails at lines of police and National Guard soldiers.
Energy Minister Luis Motta said late on Tuesday "a right-wing terrorist plan to paralyze the country" had cut a submarine cable that provided electricity to the palm tree-studded Caribbean island of Margarita, plunging it into darkness.
The president of state oil company PDVSA, Eulogio Del Pino, said "terrorists" had captured a company tanker truck in the western state of Lara, tweeting pictures of it in flames.
The opposition scoffs that an inept government blames Maduro critics as a smokescreen for rampant crime and lack of maintenance that have Venezuela's infrastructure creaking. (Additional reporting by Andreina Aponte and Eyanir Chinea; Editing by Andrew Cawthorne and W Simon)