Student protest leaders in Venezuela called a march with white flowers for peace Thursday after another night of violent disturbances wracking the capital Caracas and other cities.
Venezuelan opposition leader Henrique Capriles speaks to reporters in Caracas on February 20, 2014
President Nicolas Maduro angrily rejected US and other calls for dialogue as the protests, which have left four people dead, entered their third week.
Demonstrators -- students and opposition parties -- are angry over rampant street crime, runaway inflation, corruption and bleak job prospects in the country with the world's largest proven oil reserves.
Opposition leader Henrique Capriles, who has kept a low profile during the protests, on Thursday challenged Maduro to prove his claims that the demonstrations were part of a conspiracy to overthrow his government.
"Is this a coup or an auto-coup?" he asked. "The only one who has talked about a coup d'etat has been government. It is a fabrication by government actors," he said.
Prominent opposition leader Leopoldo Lopez, who has helped spearhead the protests, is meanwhile being held at a military jail, where his lawyers say he could remain for up to 45 days awaiting trial.
Lopez, a 42-year-old Harvard-educated economist, has been charged with instigating violence, property damage and criminal association -- but not murder, as Maduro had threatened.
- White flowers -
The student federations that have organized the protests across the country on Thursday called on "Venezuelan civil society to respond to the violence with white flowers."
The students also convened a rally, with flowers, in Las Mercedes, an upscale Caracas neighborhood of embassies, trendy restaurants and luxury condominiums.
The government meanwhile ordered a battalion of paratroopers to the border city of San Cristobal, where the student protests began on February 4, in response to what he said were reports of Colombians crossing "to carry out paramilitary missions."
In a televised news conference, he said a "de facto curfew" already was in place on the border, and he suggested that former Colombian president Alvaro Uribe was behind the border activity.
Venezuelan police fired tear gas and buckshot to disperse hundreds of anti-government protesters late Wednesday amid scenes of strife in the eastern part of the city, where opposition to the leftist government runs highest.
Burning barricades, police assaults, and intimidating sweeps by pro-government civilians on motorcycles kept residents on edge through the night.
The archbishop of Caracas appealed to the government to rein in "armed groups" who he said were "acting freely, with impunity."
"How is it possible that there could be eight or nine wounded in Valencia and a girl dead in the vilest manner simply because an armed group attacked a peaceful protest," Cardinal Jorge Urosa Savino said.
He was referring to the latest fatality, a 21-year-old beauty queen who was shot in the head Tuesday at a protest rally in the northern city of Valencia.
When reports first linked violence in an earlier shooting incident February 12 to armed groups that appeared to be working in concert with security forces, Maduro said those groups had no place on the government's side.
"I do not accept violent groups in the Chavismo camp," he said Saturday.
But Wednesday night, columns of men on motorcycles with no tags were seen moving menacingly through the eastern neighborhoods of La Castellana and Los Palos Grandes led by pick-up trucks loaded with individuals with megaphones.
In nearby Chacao, another opposition bastion that had been quiet for three previous nights, hundreds of protesters blocked the streets with burning garbage and rubble.
The police responded with water cannons, tear gas and buckshot while men on motorcycles began to open fire, sending protesters fleeing into neighboring buildings.
- 'Unjust justice' -
Moments before his arrest Tuesday, Lopez -- who founded the opposition People's Will party -- told thousands of his supporters he hoped it would highlight the "unjust justice" in Venezuela.
Obama, speaking during a visit to Mexico for a trade summit, on Wednesday urged Venezuela to release detained protesters and address the "legitimate grievances" of its people.
But the Maduro government shot back Thursday, saying it "emphatically repudiates" Obama's remarks and accusing him of "a new and crude interference in the internal affairs of our country."
On Sunday, Maduro ordered the expulsion of three US diplomats, accusing them of meeting student leaders to conspire under the guise of offering them visas. Washington denies the allegations.
The Panamanian ambassador to Caracas was called in after similar calls for a dialogue by that country.