“I was very scared the children would be recruited,” said Mr. Ranoque, who like others spoke by phone. He added that the country’s armed groups “have no respect — they are capable of recruiting a child as young as 2.”

The rescue of the children last week has provided a rare moment of unified celebration in a deeply divided nation, with broad swaths of society, from left to right, praising the work of the search team. Gustavo Petro, the country’s leftist president, called the rescue “magical,” and Iván Duque, his conservative predecessor, called it “a miracle.”

But the story of the children — Lesly, Soleiny, 9, Tien, 5, and Cristin, 1 — all from the Huitoto Indigenous group, is also a stark reminder of the dangers faced by thousands of rural Colombian children every day.

For decades the country has been terrorized by armed groups, including the Revolutionary Armed Forces of Colombia, or FARC. In 2016, the FARC agreed to lay down its arms. But the state never took control of many places where the rebels once flourished.