As tensions rose on both sides of the border, Maduro severed diplomatic relations with Colombia over its backing for his rival, who had crossed into the neighboring country for the handover of the aid.
"I have chose to break off all political and diplomatic relations with the fascist government of Colombia", Maduro told a huge rally of his supporters in the capital Caracas.
Guaido has set a Saturday deadline for the entry of humanitarian aid, saying as many as 300,000 Venezuelans are in dire need of food and medicines after years of shortages and malnutrition.
"The concert is an huge help because this type of initiative was necessary to open our eyes and pressure the Venezuelan government", said Wendy Villamizar, a 32-year-old Venezuelan woman wearing a cap with her country's yellow, blue and red tricolor.
We officially announce that the first shipment of humanitarian aid has now entered our border with Brazil.
Perez said he was beaten with sticks a few hours later by members of a pro-Maduro gang while taking other wounded people to a hospital in Santa Elena de Uairen, on the Venezuelan side.
Guaido's move to assume the interim presidency and worldwide backing has galvanized Venezuela's opposition, which has vowed to keep protesting until Maduro steps down.
"We didn't know what we were getting into at the time", Ocampo said Thursday.
Two hundred families trapped by Islamic State in Syria, U.N. says
The opposition's Syrian Civil Defense said the shelling killed five people including two children and also wounded five others. Dino, a 26-year old fighter who has fought jihadists for years, on Monday said he was glad the battle was drawing to an end.
The violence came just hours before dueling concerts were to begin on the country's western border with Colombia, where much of the USA -supplied aid is being stored in a warehouse.
"The situation is critical and we should be all united to allow the aid to pass", said shopkeeper Jeremy Ortega, 21.
Elsewhere, Venezuelan National Guard forces fired tear gas and rubber bullets at several crossing points on the Colombia border, pinning down demonstrators seeking to reach humanitarian aid stockpiled on the other side.
The socialist president, who took power in 2013 and was re-elected in an election previous year widely viewed as fraudulent, has declared Venezuela's southern border with Brazil closed and threatened to do the same with the Colombian frontier ahead of the opposition's plan to bring in the aid today.
Self-proclaimed interim president Juan Guaido announced his followers on Saturday will try to force through convoys of US aid from Colombia into Venezuela.
"The people of Venezuela are not begging, they're resisting a dictatorship, the onslaught of oppression", Guaido told a news conference in Cucuta after the concert.
Venezuela's Pemon indigenous community use unofficial border pathways to cross into Brazil to buy food.
The troops had earlier blocked people from crossing the border into Cucuta, where many Venezuelans now work, shop or send their children to school amid Venezuela's continued economic collapse.
Maduro has also shut the Brazilian border and the maritime border with nearby Dutch Caribbean islands.
Guaido declared himself acting president on January 23 until new elections are held and was recognized by Australia, Canada, Columbia, Peru, Ecuador, Paraguay, Brazil, Chile, Panama, Argentina, Costa Rica and the U.S. The European Parliament took a step in the same direction.