Thousands of people have crossed to Colombia after Venezuela opened their common border to allow its people to buy food and medicine, officials said on Sunday.
The frontier, closed by Venezuela last August as part of a crime crackdown, was to open for 12 hours.
Venezuela is going through a deep economic crisis and many say they struggle to feed their families.
Last week, about 500 Venezuelan women broke through the border controls in search of food.
President Nicolas Maduro ordered the border closure because, he said, the area had been infiltrated by Colombian paramilitaries and gangs.
The measure also prevents subsidised goods from being smuggled from Venezuela into Colombia.
In the first two hours, some 6,000 people crossed the border between San Antonio del Tachira, in Venezuela, and Cucuta, in Colombia, an official told the BBC’s Natalio Cosoy, in Cucuta.
Supermarkets were crowded with Venezuelans buying basic goods such as rice, oil and flour, which are expensive in their country because of the shortages, our correspondent added.
An unnamed woman who crossed with her husband and two young children told EFE news agency it was “unfair” to keep the border closed.
“We are from San Antonio, and the reality is that we do not have any food to give to our children.”
Venezuelans who want to cross into Colombia in states where the border has been closed need a special permit to do so.
But as the scarcity of food gets worse in Venezuela, many have crossed the porous border illegally.