Some accuse Venezuelan army of using excessive force in operation against armed groups near Colombia-Venezuela border.
ALESSANDRO RAMPIETTI: José Gregorio [INAUDIBLE] is disheartened as he shows us a video of his home destroyed in clashes between the Venezuelan Army and a Colombian rebel group.
INTERPRETER: It's really sad seeing how easy it is to lose everything you've built with great sacrifice.
ALESSANDRO RAMPIETTI: He and his family fled a week ago from a town across the border as Venezuelan soldiers moved into their neighborhood and bombs fell from the sky. They left in such a hurry that he didn't have time to put shoes on. He is one of almost 5,000 people who have sought refuge in one of the 18 shelters set up in and around the border town of Arauquita, in Colombia.
They've come here after the Venezuelan Army started an unprecedented operation against Colombian armed groups they had long tolerated in their territory. Many are accusing security forces of abuses and, in at least one case, of extrajudicial killings in Venezuela.
INTERPRETER: I'm afraid of going back to Venezuela because I don't know what they would do to us. The soldier killed our neighbor, her kids, and her husband. They say we're all guerrillas.
ALESSANDRO RAMPIETTI: The influx of refugees, many young children, is overwhelming this town.
On Sunday, the Colombian government set up a command post to manage the worsening humanitarian situation with the help of the United Nations Refugee Agency and other organizations.
INTERPRETER: The priority is the humanitarian assistance of those who entered the country to guarantee their health, food, and hopefully, guarantee a swift return.
ALESSANDRO RAMPIETTI: The Colombian government is planning for the shelters to operate for at least two weeks, even if local Venezuelan authorities said on Saturday that people could go back.
Despite assurances from the Venezuelan government that the situation is under control, we heard more explosions coming from the other side just a few hours earlier. And more people are arriving, fleeing from Venezuela into Colombia, eight days into this crisis.
The situation is very difficult. This man says, "there is no food. We don't know what we will do."
Back at the shelter, most people say there are no guarantees for a safe return. For now, José Gregorio is happy he and his family at least have food and a shared roof over their heads.
Alessandro Rampietti, Al Jazeera, Arauquita.