US Vice President Mike Pence will meet with Venezuela's self-declared interim president and opposition leader, Juan Guaido in Bogota, Colombia Monday, following a weekend of violent clashes along Venezuela's borders with Colombia and Brazil.
Deaths and injuries: Nearly 300 people are estimated to have been injured in clashes between Venezuelan troops loyal to President Nicolas Maduro and protesters in areas near the country's border over the weekend. The opposition says five people were also killed. CNN has not verified those numbers.
Aid deliveries: Trucks carrying supplies were stopped at most spots Saturday. Witnesses said two trucks were set ablaze while attempting to cross into Venezuela from Colombia.
US response: US Secretary of State Mike Pompeo condemned the actions of Maduro's government and said the US would "take action against those who oppose the peaceful restoration of democracy in Venezuela." Pompeo wrote on Twitter: "What kind of a sick tyrant stops food from getting to hungry people? The images of burning trucks filled with aid are sickening."
Tensions with Colombia: Maduro on Saturday told supporters he was breaking all diplomatic relations with Colombia and calling for its ambassadors and consuls to leave Venezuela. Colombia ordered its diplomats to leave immediately for their safety.
Defections: Colombia's customs agency said Sunday that 104 members of Venezuela's security forces had defected, entering Colombia.
US will offer Guaido 'unwavering support'
While in Colombia, Pence will also address a meeting of the Lima Group -- a diplomatic body created by leaders mostly from Latin American countries to help mitigate the Venezuelan crisis.
The White House said Pence would "voice the United States' unwavering support for interim President Juan Guaido and highlight the Venezuelan people's fight for democracy over dictatorship."
Guaido, who arrived in Bogota Sunday, is battling President Nicolas Maduro for control of Venezuela. He has called for other nations to send aid to the country in response to worsening food and medicine shortages. But Maduro -- who won re-election in a widely-criticized vote last year -- denies that a humanitarian crisis exists in Venezuela and suggests that aid efforts are part of a US plot to orchestrate a coup.
The dispute led the Venezuelan military -- on Maduro's order -- to block aid convoys at the country's border on Saturday.
Trucks set ablaze during aid attempt Saturday
Trucks carrying supplies were stopped at most spots Saturday. Witnesses said two trucks were set ablaze while attempting to cross into Venezuela from Colombia.
CNN cannot independently confirm the incident or the circumstances of how the two trucks were set on fire.
Venezuelan Communications Minister Jorge Rodriguez accused Guaido supporters of burning the trucks.
While a CNN team saw incendiary devices from police on the Venezuelan side of the border ignite the trucks, the network's journalists are unsure if the trucks were burned on purpose.
Humanitarian aid moved through the Brazilian-Venezuelan border in Pacaraima, according to Maria Teresa Belandria, Venezuela's opposition-appointed ambassador to Brazil.
Workers blocked from entering Colombia
Venezuelan soldiers faced off against protesters who were demanding to cross the border at Ureña to go work in Colombia, according to a CNN crew that witnessed the scene at the Tienditas Bridge.
The Colombian foreign minister said 285 people were hurt, with 37 requiring hospitalization, after the Venezuelan National Guard fired tear gas and rubber bullets at protesters near the Colombian border Saturday.
The Venezuelan Government's special envoy for the Tachira State -- which borders Colombia -- said Sunday more than 300 people were injured Saturday.
"The Bolivarian forces registered 315 injured, some by firearm others by Molotov cocktails," envoy Freddy Bernal said. "We registered no deaths despite the violent attacks for more than 15 hours of battle" by groups on the international bridges fighting "against thousands of patriots who fought and defended themselves."
Bernal did not specify whether the injured toll includes members of the National Guardsmen, or strictly civilians fighting alongside the National Guard. CNN has not independently verified the numbers of the injured in these clashes.
Reports of fatalities
National Assembly Representative and Guaido supporter Adriana Pichardo told CNN that at least five people were also killed in clashes with Venezuelan security forces.
CNN cannot independently confirm the number of fatalities, but Michelle Bachelet, the UN high commissioner for human rights, said there were four deaths and 300 injuries Friday and Saturday.
CNNE crews heard shots beings fired and saw tear gas being thrown in the Brazilian-Venezuelan border town of Pacaraima, Brazil Saturday.
The governor of Roraima, the Brazilian state bordering Venezuela, declared a state of medical emergency on Sunday, according to a press release from the Roraima Ministry of Health.
Governor Antonio Denarium is quoted in the release saying the state's largest hospital, in the capital Boa Vista, is "at the brink of collapse" following the influx of victims injured in clashes across the border in Venezuela.
Rocks and rubber bullets in Sunday clashes
Sunday was quieter. Small clashes broke out again at a town near the border with Colombia. CNN's team in Ureña, Venezuela, saw dozens of people throwing rocks toward Venezuela's National Guard, who fired back with rubber bullets. There was no report on injuries.
Rodriguez said that the country's security forces had protected the border in "exemplary" fashion.
But Bachelet, the UN official, described "disgraceful scenes." "The Venezuelan government must stop its forces from using excessive force against unarmed protesters and ordinary citizens," she said.
In a statement Sunday, UN Secretary General António Guterres said he is "following with increasing concern" the tensions in Venezuela.
Guterres called "for violence to be avoided" and "for lethal force not to be used in any circumstances."
Meantime, Colombia's customs agency said Sunday that 104 members of Venezuela's security forces have defected, entering Colombia. The development is a sign that Maduro's grip on the military -- control of which is seen as integral to forcing new elections -- could be waning.
But Maduro put out a defiant message Sunday.
"The people are united in the streets, mobilized and alert in every corner of the country," he said on Twitter. "I call on men and women of goodwill, not to lower their guard and to stay in the fight to preserve Venezuela's peace. Long live the Rebel homeland!"