ELN rebels released 18 of their captives, while beginning negotiations with families of the remaining 35 over ransom terms. ELN has conducted four such mass kidnappings in the last 18 months. The ELN extracts millions of dollars from the families of the victims. Negotiations often drag on for a long time. For example, of 41 people kidnapped in a plane hijacking in April, 1999, one has since died in captivity and negotiations drag on for three others. The rebels sometimes ask for more money than the families can come up with. As a result of these kidnappings, thousands of middle and upper class families are fleeing the country. Many more carefully watch their movements.