at least some sympathetic figures included in the citizens assembly. That could distract them from the drumbeat of near daily street protests that they have managed to keep up for four weeks, political analyst Luis Vicente Leon said.

"It's a way of calling elections that uses up energy but does not carry risk, because it's not a universal, direct and secret vote," Leon said. "And it has the effect of pushing out the possibility of elections this year and probably next year as well."

The constitution was last rewritten in 1999, early in the 14-year presidency of the late Hugo Chavez, who began Venezuela's socialist transformation.

The leader of the opposition-controlled National Assembly, Julio Borges, called the idea of a constitutional assembly a "giant fraud" by Maduro and his allies designeddone more than a dozen times in four weeks of near-daily protests. Officers launched tear gas and chased people away from main thoroughfares as the peaceful march turned into chaos.

Opposition lawmaker Jose Olivares was hit in the head with a tear gas canister and was led away with blood streaming down his face. Some demonstrators threw stones and gasoline bombs and dragged trash into the streets to make barricades.

A separate government-sponsored march celebrating May Day went off without incident in the city.

At least 29 people have died in the unrest of the past month and hundreds have been injured.

People of all ages and class backgrounds are participating in the protests. The unrest started in reaction to an attempt to nullify the opposition controlled-congress, but has become a vehicle