Venezuelan President Nicolás Maduro has announced he is closing the border with Brazil on Thursday night as a row over foreign humanitarian aid continues, the BBC reports.
Maduro went on TV to say that he was also considering shutting the border with Colombia to stop the opposition bringing in relief.
He denies any crisis and calls the aid delivery plans a US-orchestrated show.
Opposition leader Juan Guaidó is leading a convoy to the Colombian border from the capital Caracas.
Mr Guaidó declared himself interim leader during anti-government protests last month and is recognised by dozens of foreign states, including the US.
Scuffles broke out and tear gas was fired when the convoy of buses and cars was briefly stopped by security forces on a road near Mariara, west of Caracas, but they later moved on.