A 10-year-old girl abducted nearly three weeks ago has been freed, Colombia's President Juan Manuel Santos said via Twitter, after a kidnapping that shocked the nation. "Let's celebrate the liberation of Nohora Valentina," he wrote. The girl, Nohora Valentina Munoz, was on her way to school with her mother on September 29 when she was abducted by unidentified gunmen. The girl's mother was freed shortly after the abduction. The victim is the daughter of Jorge Munoz, mayor of the Arauca town of Fortul. Without elaborating, Santos in his Twitter message thanked the International Committee of the Red Cross (ICRC) for its role in helping secure the girl's release. The child's father was cautiously hopeful about the news. "If the president says it, it must be true. I'm glad," Munoz said. Santos' message did not make clear if authorities now know who was responsible for abducting the girl. Although immediate suspicion fell on Revolutionary Armed Forces of Colombia rebels, the group said on its website last week that it had nothing to do with her kidnapping. The kidnapping took place in a region where security forces clashed with National Liberation Army (ELN) guerrillas, members of the second largest rebel group in the South American nation. But a recent statement attributed to ELN rebels in Arauca said the kidnapping was by the FARC -- the country's oldest and biggest insurgent group. FARC said it issued the denial to the public "to avoid being manipulated". It also said the abduction suggested an attempt by military intelligence agencies to use psychological warfare "in order to influence regional and national opinion" to support the war on the rebels. Earlier this month the girl's father issued a plea to the kidnappers while acknowledging there was "no real clarity about who the perpetrators of the kidnapping are and what they want." Colombia's Defense Minister Juan Carlos Pinzon last month offered a 100 million peso ($52,000) reward for information leading to the girl's release.