Venezuela street protests again turn deadly as overhaul of constitution begins More than 30 people have been killed in protests in Venezuela this year.

 -- Street protests in Venezuela claimed at least one more fatality on Wednesday, bringing the total number of people killed to more than 30 in several weeks of unrest.

Thousands of Venezuelans took to the streets as president Nicolas Maduro began the process of overhauling the country's constitution -- a move that has raised the stakes in a bitter standoff between Maduro's government and a growing opposition.

"I see congress shaking in its boots before a constitutional convention," Maduro said, referring to the opposition-controlled National Assembly in a speech to his supporters.

U.S. State Department Deputy Assistant Secretary of State for Western Hemisphere Affairs Michael Fitzpatrick said the government's constitutional convention “overrides the will of the Venezuelan people and further erodes Venezuelan democracy,” on Tuesday.

A fresh wave of unrest has engulfed Venezuela in the past month amid a severe economic and political crisis. Venezuela's economic output shrank some 18 percent last year and annual inflation this year is projected to top 700 percent, according to the IMF.

Protesters in the capital Caracas faced off with police in a series of violent clashes on Wednesday. Demonstrators lit vehicles on fire and police launched tear gas and deployed armored vehicles to stop crowds from reaching the steps of the National Assembly, the Associated Press reported.

Some 1,700 people have been arrested at protests since the beginning of April, nearly 600 of whom remain behind bars, according to Penal Forum, a Venezuelan NGO that tracks arrests and violence surrounding the protests.

A wave of protests back in 2014 resulted in more than 40 deaths and thousands of arrests.

In a dramatic scene caught by a photographer at one of the Wednesday protests, a man was severely burned when the gas tank of a police motorcycle exploded during clashes between protesters and government security forces.

The United Nations has called for Venezuela's government to allow Venezuelan citizens to peacefully protest.

“We are gravely concerned about allegations of excessive and indiscriminate use of force during the protests, as well as arbitrary detentions and killings,” the United Nations Human Rights Council said in a statement released last month.

Maduro has blamed the protest organizers for the violence and dismissed the recent uprising as a U.S.-backed conspiracy to remove his socialist government from power.

The Associated Press contributed to this report.