(Adds details on skirmish, quote from National Guard, context)
By Girish Gupta
CARACAS, March 6 (Reuters) - A Venezuelan soldier and a motorcyclist died in a confused melee sparked by the opposition's barricading of a Caracas street, officials said on Thursday, boosting the death toll from nearly a month of violence to 20.
Demonstrators have for weeks staged rallies and set up barricades to demand the resignation of President Nicolas Maduro, leading to clashes with security forces and government supporters.
Motorcycle drivers clearing a barricade in the middle-class neighborhood of Los Ruices were attacked by residents from nearby buildings who threw rocks and later shot at them, National Guard Gen. Manuel Quevedo told Reuters.
The motorcyclist who was killed, Jose Cantillo, who was in his early twenties, was shot in the neck, Quevedo said.
"Make no mistake, the National Guard and the armed forces are going to continue patrolling the streets to restore order," he said in an interview at the scene of the events.
A second motorcycle driver was wounded and is in critical condition, President Maduro said in a televised broadcast.
Troops arrived in some 20 armored vehicles and used tear gas to disperse several hundred demonstrators, Reuters witnesses said.
Residents continued throwing rocks from above, but angry passers-by threw them back and attempted to force their way into buildings in an apparent attempt to find the assailants.
The troops used riot shields to shelter other soldiers from the rain of stones as they knocked down barricades and cleared debris including a car that demonstrators had burned in the morning, the witnesses said.
Maduro on Wednesday called on pro-government organizations including groups known as 'colectivos,' which opposition leaders describe as paramilitary groups, to help keep order in the streets.
The demonstrations began as sporadic protests against chronic product shortages and inflation that reached 56 percent in 2013, but expanded into a nationwide movement after three people were killed after a Feb. 12 march, unleashing the country's worst unrest in a decade.
Since then the protests have been more focused on complaints of excessive use of force in breaking up protests and demands for the release of imprisoned activists including Leopoldo Lopez, who spearheaded the nationwide protest efforts.
Though street protests helped briefly topple the late socialist leader Hugo Chavez in a botched 2002 coup, there seems little chance the current unrest could lead to a Ukraine-style overthrow.
Government supporters slam the protests as dangerous and damaging disruptions of public order that have prevented sick people from receiving emergency treatment and stopped citizens from carrying out day-to-day activities.
Maduro, a former bus driver who calls himself the 'son' of the late Chavez, has called for a meeting of presidents of the Unasur group of Latin American nations to address the unrest.
"Over time we are going to shut them down," Maduro said in a televised broadcast on Thursday afternoon. "They'll be remembered as violent vandals who have killed good men and women of this country."
Maduro on Wednesday cut ties with Panama on charges the country's president was conspiring with the United States to intervene in Venezuela's affairs. During a rally on Thursday he gave the Panamanian ambassador and three other diplomats in Venezuela 48 hours to leave the country.
The rally also included Hollywood actor Danny Glover, a long time supporter of Venezuela's revival of socialism who met with Maduro as part of Wednesday's first anniversary of Chavez's death.
"I'm very proud to be here with you as we commemorate and celebrate a true man of the people, Hugo Chavez; his memory lives with us," Glover told a crowd of government supporters clad in signature red T-shirts.
A Venezuelan television network on Wednesday premiered U.S. filmmaker Oliver Stone's documentary called "My Friend Hugo."
The protests have been a mix of peaceful demonstrations by student leaders and violent exchanges between security forces and hooded protesters hurling rocks and Molotov cocktails.
Barricades made of debris and burning trash have angered even government critics and have led to fights between demonstrators and drivers attempting to push their way through.
Protesters have increasingly defied opposition leaders' calls to rein in violence and focus on convincing skeptical Maduro supporters to change their views.
One prominent opposition deputy was widely pilloried via Twitter this week for calling on anti-government demonstrators to respect Wednesday's celebration of the anniversary of Chavez's death from cancer. (Reporting by Eyanir Chinea; Writing by Brian Ellsworth; Editing by James Dalgleish; and Dan Grebler)