Caracas, Venezuela (CNN) Venezuelan President Nicolas Maduro severed diplomatic relations with Colombia on Saturday as violence broke out along the two countries' borders, where international aid intended for Venezuela is awaiting transport.

After opposition leader Juan Guaido named Saturday as the deadline for the aid to cross the border, Maduro vowed to stop the supplies from coming into the country, calling the plan part of a coup attempt.

These are the highlights from Saturday:

• At least five people were killed in clashes with Venezuelan security forces on Saturday, National Assembly Representative Adriana Pichardo told CNN, without giving further details. Pichardo, who supports Guaido, said 51 people were arrested. CNN cannot independently confirm the number of fatalities.

• 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.

• Trucks carrying supplies were blocked at most spots, but two trucks carrying Brazilian humanitarian aid crossed into Venezuela on Saturday without incident, the office of communications for the Brazilian presidency said.

• At a rally in the capital of Caracas, Maduro said he was breaking relations with neighboring Colombia and threatened the United States with "the strength of the Venezuelan armed forces."

• Opposition leader Guaido vowed Saturday night that "We will not stop until we see freedom in Venezuela."

• US Secretary of State Mike Pompeo attacked Maduro on Twitter , saying, "What kind of a sick tyrant stops food from getting to hungry people? The images of burning trucks filled with aid are sickening."

Trucks set on fire

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 protesters chanted, "We want to work!" as the National Guard fired tear gas to disperse them. Men with shirts covering their faces started throwing rocks toward the guard members.

CNN's team in Ureña witnessed Venezuelan Armed Forces fire tear gas at three members of the opposition-leaning National Assembly while they were attempting a peaceful mediation with protesters.

Journalist Stefano Pozzebon said three congressmen, two men and one woman, raised their hands in the air Saturday afternoon and started slowly walking toward a human barricade of Venezuelan armed forces when the soldiers fired tear gas at them. The members of congress then pulled back to a safe location among the protesters.

Also Saturday, humanitarian aid moved through the Brazilian-Venezuelan border in Pacaraima, according to Maria Teresa Belandria, Venezuela's opposition-appointed ambassador to Brazil.

Ya estamos cargando la ayuda humanitaria desde Boa Vista Gracias Brasil. 🇧🇷 Gracias 🇺🇸 #VamosBien pic.twitter.com/GrJLOUbZBO — Maria T Belandria (@matebe) February 23, 2019

But trucks were stopped at other border points. Witnesses said the two trucks were set on fire as Venezuelan security forces were firing tear gas against volunteers unloading aid on the Francisco de Paula bridge. CNN cannot independently confirm the incident or the circumstances of how the two trucks were set on fire.

A ship carrying humanitarian aid to Venezuela received direct threat of fire by Venezuelan military ships Saturday, according to a news release from Puerto Rico Gov. Ricardo Rossello.

"This threat constitutes a serious violation of a humanitarian mission, composed of American citizens. It is unacceptable and outrageous," Rossello said. The governor ordered the ship to leave the area.

Maduro: 'My patience has run out'

Maduro denies that a humanitarian crisis exists in Venezuela and suggests that aid efforts are part of a US plot to orchestrate a coup.

At a large rally in Caracas on Saturday, he dared the opposition to call for elections and called Guaido a "clown" and a "US puppet."

Maudro told supporters he is breaking all diplomatic relations with Colombia and is calling for its ambassadors and consuls to leave Venezuela.

He gave the Colombian ambassadors and consuls 24 hours to get out of the country. Colombian Foreign Minister Carlos Holmes Trujillo said all the diplomats were ordered to leave immediately for their safety.

"My patience has run out. I can't continue to tolerate the aggressions against Venezuela that are being carried out by the Colombian government," Maduro said.

He also threatened the United States: "If the empire dares to attack, they will be received by the strength of the Venezuelan armed forces."

Pompeo, the US secretary of state, blasted Maduro on social media, calling him "a sick tyrant" and saying, "The U.S. will take action against those who oppose the peaceful restoration of democracy in #Venezuela. Now is the time to act in support of the needs of the desperate Venezuelan people."

The U.S. will take action against those who oppose the peaceful restoration of democracy in #Venezuela. Now is the time to act in support of the needs of the desperate Venezuelan people. We stand in solidarity with those continuing their struggle for freedom. #EstamosUnidosVE pic.twitter.com/XfLEsyT6Rj — Secretary Pompeo (@SecPompeo) February 24, 2019

The United States recognizes Guaido as the legitimate president of Venezuela. A White House official said Saturday that US Vice President Pence will meet with Guaido on Monday in Bogota, during Pence's visit to Colombia.

Guaido, who declared himself acting president last month, has been working with global partners to bring Venezuelans desperately needed food and medical supplies.

He spoke at a joint press conference with President Ivan Duque of Colombia in Cucuta, Colombia, on Saturday night and urged people not to be loyal to those that burn medicine in front of the sick.

"Today the world has seen the tyranny that we struggle with in Venezuela. People celebrated that hospitals could not get access to the aid." Guaido said.

"We must move forward and seek the necessary help to stop the tyranny," Guadio said, adding "We will not stop until we see freedom in Venezuela."

Guaido tweeted later Saturday that aid had reached Venezuelan territory, including an image of trucks blocked by the military.

¡Atención Venezuela!



Anunciamos que los camiones de la ayuda humanitaria provenientes de Colombia ya están en territorio venezolano.



El régimen usurpador está impidiendo su paso.



No podrán con nuestra decisión irreversible de vivir en libertad.



#23FAvalanchaHumanitaria pic.twitter.com/PBFJnRnaJm — Juan Guaidó (@jguaido) February 23, 2019

Defections on the border

More than 60 Venezuelan security forces defected to Colombia,Trujillo said in a news conference from Cucuta on Saturday. Among them were two members of the Bolivarian National Guard who fled with their families, Colombian immigration authorities said.

A Venezuelan man also "turned himself in," Colombian immigration authorities said.

Some of the troops abandoned their posts at the Simon Bolivar International Bridge on the Colombia-Venezuela border and requested help from Colombia's immigration department.

Guaido tweeted a video he said shows Venezuelan soldiers saluting him as their commander in chief.

Aid stacked on Colombian border

The United States announced Friday that it was preparing to bring in aid through another route.

The United States has so far delivered batches of relief supplies to a border town in Colombia , including food and hygiene kits, ready-to-use supplementary foods and high-energy biscuits. It's pledged $20 million to help Venezuela, and other countries including Canada, the UK and Germany have chipped in, too.

Colombian President Duque said Saturday that aid piled up in his country should be allowed into Venezuela.

"We demand that its entry is allowed in a peaceful manner to the Venezuelan territory for the benefit of those who need it," said Duque, standing alongside Guaido at a press conference in Cucuta, Colombia, near the Venezuelan border.

A standoff over aid delivery led to violence Friday at a Venezuelan town near the border with Brazil, killing two people and injuring 17 others, local authorities said.

The violence occurred between a local indigenous community and the military near Gran Sabana, said the town's mayor, Emilio Gonzalez. He told CNN the military opened fire on an indigenous group trying to facilitate the passage of aid into Venezuela.