Venezuelan troops kill one near Brazil

Defying orders banning him from leaving Venezuela, opposition leader Juan Guaido made a surprise appearance at the end of star-studded aid concert in neighbouring Colombia, joining thousands of other Venezuelans in pressuring President Nicolas Maduro into allowing the delivery of emergency food and medicine.

In Venezuela, a much smaller crowd gathered for a rival, three-day "Hands Off Venezuela" festival being organised by Maduro. Even as several million Venezuelans flee the country and those who remain struggle to find basic goods like food and antibiotics, the embattled president claims the relief effort led by Guaido is a US orchestrated ploy to oust him from power.

It's not clear how Guaido sneaked into Colombia - in one video circulating on social media he appears running across a bridge near the Venezuelan town of Urena, while in another he could be seen boarding a helicopter belonging to the Colombian air force.

But once he arrived at the giant stage located next to the Tienditas bridge connecting the two countries he was greeted like a rock star himself. Thousands of Venezuelans shouted "Juan arrived! Juan arrived!" when they spotted him donning a white shirt and accompanied by a large contingent of Colombian security as he made himself through the front of the crowd.

The presidents of Colombia, Chile and Paraguay were on hand to be the first foreign heads of state to embrace the 35-year-old lawmaker since he declared himself interim president a month ago at an outdoor rally.

The optimistic mood at the Live Aid-style concert opened in the Colombian border city of Cucuta couldn't mask underlying tensions a day before Maduro's opponents embark on a risky strategy to undermine Maduro and bring in the aid being amassed along three of Venezuela's borders. But the crowd reacted with joy when Guaido suddenly appeared.

Thousands of kilometres away, near a crossing with Brazil, a member of an indigenous tribe was killed and 22 more injured in clashes with security forces who enforced Maduro's orders to keep out the aid.

Hours before the concert in Cucuta began, dozens of Venezuelans hiked across the border through high bushes on an unmarked trail. They carried ice boxes, snacks and water and whispered directions as they kept a close eye out for Venezuelan soldiers.

"This concert happens once in a lifetime," 19-year-old Shirley Duran said. "It will be a great opportunity for so many poor people who are suffering under the heat, who are hungry, jobless. At last they'll have something to enjoy."

British billionaire Richard Branson organised the "Live Aid Venezuela" concert, which featured dozens of Latin musicians performing on a bridge-side stage not far from where Maduro's government has placed a giant shipping container and tanker to prevent the delivery of US-supplied food and medical kits.

Days after Branson launched his concert, Maduro's government announced that not only would they hold a rival festival but that they would also deliver over 20,000 boxes of food for poor Colombians on Friday and Saturday.

In contrast to the festive spirit in Cucuta, most of the acts at the pro-government show were lesser known, the crowd of a few hundred much older and some attendees reported being bussed in by the government from as far away as the capital, Caracas.