BOGOTA - Colombia's rebels freed only one of three hostages they have promised to release on Sunday, the International Committee of the Red Cross said.

Police officer Carlos Ocampo, who was kidnapped in December 2010, was freed by the Revolutionary Armed Forces of Colombia (FARC) on Sunday, the Red Cross said. It did not give the reason why the other two hostages were not released.

"Ocampo was released by the FARC in a rural zone of Tolima department. Unfortunately the release of officer Solorzano and soldier Sanmiguel, which is meant to be carried out today, is not possible," said Red Cross spokesman Cristina Rivera.

Unconfirmed reports said family members of the hostages said bad weather was the reason for the delay.

The FARC has announced it would release three hostages, including Carlos Ocampo, senior police officer Guillermo Solorzano and army soldier Salin Sanmiguel on Sunday.

Ocampo has been taken to the airport at Ibague by a humanitarian mission formed by Red Cross stuff and a former senator.

He is the fourth hostage released by the FARC in the past week. The rebel group released councilor Marcos Baquero on Wednesday, and two days later it released marine Henry Lopez and councilor Armando Acuna.

The FARC, Latin America's oldest guerrilla group, was once a strong anti-government force and was notorious for its drug trafficking and kidnapping activities. But the group has suffered huge setbacks due to a determined government security drive since 2002 and backtracked into remote mountains and jungles.