The United States, which is among dozens of Western nations to recognize opposition leader Juan Guaido as Venezuela’s legitimate president, has been stockpiling aid in the Colombian frontier town of Cucuta to ship across the border this weekend.

With tensions running high after Guaido invoked the constitution to declare an interim presidency last month, Maduro has denied there is a humanitarian crisis in Venezuela despite widespread shortages of food and medicine and hyperinflation.

Maduro, who took power in 2013 and was re-elected in an election last year widely viewed as fraudulent, says opposition efforts to bring in aid are a U.S.-backed “cheap show” to undermine his government.

The socialist president has declared Venezuela’s southern border with Brazil closed and threatened to do the same with the Colombian border ahead of a Saturday deadline by the opposition to bring in humanitarian assistance.

A fundraising concert for Venezuela, backed by British billionaire Richard Branson and featuring major Latin pop stars like Luis Fonsi of “Despacito” fame, attracted tens of thousands in Cucuta on Friday.

Some political analysts say Saturday’s showdown is less about solving Venezuela’s needs and more about testing the military’s loyalty toward Maduro by daring it to turn the aid away.

With inflation running at more than 2 million percent a year and currency controls restricting imports of basic goods, a growing share of the country’s roughly 30 million people is suffering from malnutrition.

Friday’s violence broke out in the village of Kumarakapay in southern Venezuela after an indigenous community stopped a military convoy heading toward the border with Brazil that they believed was attempting to block aid from entering, according to two community leaders.

Soldiers later entered the village and opened fire, killing a woman, Zoraida Rodriguez, and her husband, and injuring several others, the leaders said. Rodriguez’s brother Guillermo Rodriguez later told Reuters that the husband was still alive but in critical condition after being shot in the stomach.

“I stood up to them to back the humanitarian aid,” community leader Richard Fernandez told Reuters. “And they came charging at us. They shot innocent people who were in their homes, working.”

Venezuela’s Information Ministry did not immediately reply to a request for comment.

The United States said it condemned the killings that have taken place in Venezuela.

“We stand with the victims’ families in demanding justice,” a State Department official said.

Meanwhile China, which along with Russia backs Maduro, warned humanitarian aid should not be forced in because doing so could lead to violence.