Transcript for Violence erupts between Venezuelan National Guard and demonstrators

That's on Monday morning after is gone. Sam, thank you. We turn now to the deepening crisis in Venezuela. Troops firing tear gas on demonstrators. In new clashes. As Nicolas maduro continues to refuse humanitarian aid from the United States. At least 60 Venezuelan troops have defected including a major army major saying, he stands with interim president Juan guaido. Reporter: Tonight, Venezuela in chaos. Violence erupting on the borders. The National Guard firing tear gas on protesters. Civilians racing to save trucks of crucial aid crossing from Colombia, catching on fire. "Look how it's burning," this woman said. Key border crossings shut down. Clashes along the border with Brazil over aid leaving at least one person dead. Demonstrators trying to clear this bridge, moving large metal Barr suddenly, members of the military switching sides. One raising his rifle over his head in surrender. It's been one month since Juan guaido declared himself interim president. He is recognized by the United States and 50 other countries. Today, guiado calling on the military to be as he puts it on the right side of history. A major in the Venezuelan army joining guiado. Saying to cheers, "And I am in this struggle with the people of Venezuela." Tonight, massive crowds gathering in the capital Caracas in support of maduro, who still controls the military and the country. The defiant leader cutting diplomatic ties with Colombia, dancing on state TV. "I will never submit, I will never surrender," he said. The United States is watching events in Venezuela very closely. National security adviser John Bolton cancelling a trip to South Korea in order to concentrate on the political crisis. And today, the president tweeting that the people there were ready to reclaim their country and their future. Tom. Julia, thank you.

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