Venezuelan forces on Saturday fired rubber bullets and tear gas to break up a crowd demanding to cross a closed border bridge to Colombia, AFP journalists reported.
"We want to work!" they chanted while facing the Venezuelan National Guard riot police who were blocking the crossing in Urena, a town in Tachira state.
Late on Friday, President Nicolas Maduro ordered the closure of all four bridges linking Tachira to Colombia.
Opposition leader Juan Guaido has massed supporters on both sides of the border to support a bid to bring in tons of US-supplied humanitarian aid from the Colombian city of Cucuta in defiance of Maduro who rejects the aid as a pretext for a US intervention.
Guaido, who proclaimed himself acting president one month ago, set Saturday for a showdown over the desperately-needed aid, essentially daring the military to stop them from bringing the aid in.
In Urena, residents demanded that the military let them cross a footbridge used to go back and forth to Colombia for work or to buy goods not available in Venezuela.
After moments of rising tension, riot police advanced and began firing teargas while some protesters responded by hurling rocks.
Some 40,000 Venezuelans cross from Tachira into Colombia every day, most returning the same day.
"I have to get through to do my eight little hours of work. What happens if I don't show up? My family depends on me," said 24-year-old Unay Velasco just before the confrontation began.
Venezuelan national guards clash with demonstrators at the border town of Ure�a after Maduro�s government ordered to temporary close down the border with Colombia on February 23, 2019