KUMARAKAPAY, Venezuela/CUCUTA, Colombia — Venezuelan troops shot dead at least one person and wounded several others on Friday near the Brazilian border, witnesses said, in the first bloodshed linked to efforts to bring aid into the South American country against the orders of embattled President Nicolas Maduro.

The killing came as a fundraising concert for Venezuela — backed by British billionaire Richard Branson and featuring major Latin pop stars — kicked off in the Colombian frontier town of Cucuta, where the United States has been stockpiling aid to ship across the border this weekend.

With tensions running high after opposition leader Juan Guaido invoked the constitution to declare an interim presidency, Maduro has denied there is a humanitarian crisis. He says opposition efforts to bring in aid area a US-backed “cheap show” to undermine his government.

Maduro 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.

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, many Venezuelans lack vital medicines and 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 as indigenous leaders in southern Venezuela said they had attempted to stop a military convoy heading toward the border with Brazil, believing the soldiers were attempting to block the entrance of foreign aid as per Maduro’s order.

The convoy entered the village anyway, opening fire to clear the way and killing a woman, Zoraida Rodriguez, according to community leaders Richard Fernandez and Ricardo Delgado.

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

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

Earlier on Friday, China’s Foreign Ministry said aid should not be forced into Venezuela lest it cause violence.

Guaido has vowed the opposition will bring in foreign aid from neighboring countries on Saturday and called on security forces to disobey Maduro and let supplies into the country suffering food and medicine shortages.

He set off toward the Colombian border on Thursday in a convoy with opposition lawmakers to oversee the effort.

“You must decide which side you are on in this definitive hour,” he wrote on Twitter. “To all the military: between today and tomorrow, you will define how you want to be remembered.”

The 35-year old has been recognized as legitimate interim president by dozens of nations over the past month including the United States, arguing that Maduro’s re-election was fraudulent.

Many countries have sent supplies to collection points in Cucuta, Brazil and Curacao.

Guaido’s move and international backing has galvanized Venezuela’s opposition, which has vowed to keep protesting until Maduro steps down. It had previously staged major protests in 2014 and 2017 that waned in the face of government crackdowns.

“Our days of repression are numbered. I think this time we will be successful,” said Leticia Ramirez, 19, who traveled to Branson’s Venezuela Aid Live concert from the Venezuelan side of the border.

Not everyone is as hopeful about ousting Maduro.

“The truth is that not even 10 concerts will make damned Maduro leave office,” said Darwin Rendon, one of the 3.4 million Venezuelans to have emigrated since 2015 to find work.

“This regime is difficult to remove,” said Rendon, who sends remittances back to his family in Caracas.

Overnight the Venezuelan government soldered three shipping containers, which it has been using to block the traffic lanes on the never-used Tienditas road bridge, to the bridge itself, Colombia’s migration agency said in a Friday statement.

Colombia will restrict border crossings on Saturday from 5 a.m. until midnight to people participating in the aid handover.

Venezuela this week also closed the maritime border with the Dutch Caribbean islands. — Reuters