The Revolutionary Armed Forces of Colombia (FARC) rebel group has released a group of 10 police officers and soldiers, who were held hostage for over 12 years. The hostages were handed over to a humanitarian mission led by the International Red Cross on Monday. “This operation in a single day allowed ten families to be reunited after being apart for so many years,” said Jordi Raich, head of the International Committee of the Red Cross delegation. The rebel group has already released about 20 other hostages, with the assistance of Brazil -- whose mediation was requested by the rebels as a measure of neutrality. FARC, Latin America's oldest rebel group, has been battling the Colombian government since 1964. The organization is believed to have an estimated 9,000 fighters operating across a large swathe of the eastern jungles of Colombia. Colombian officials say the rebels still hold more than 100 civilian hostages. In recent years, however, the US-backed Colombian military has pushed the group out of their encampments around major cities and into the dense jungles and high peaks of the Andean mountains.