BOGOTA, Colombia (CNN) -- A Colombian delegation, led by a federal senator, has left for Brazil on the first leg of a multiday journey to obtain the release of six hostages held by the FARC guerrilla group.
Colombian Sen. Piedad Cordoba has been designated by FARC rebels as the coordinator of the hostages' release.
Sen. Piedad Cordoba is heading the delegation, traveling first to San Gabriel de Cachoeira in Brazil's Amazon jungle, where the group will coordinate the hostage release.
From there, the delegation, which also includes two journalists and members of the International Red Cross, will fly in two helicopters to the jungles of San Jose del Guaviare, Colombia.
The first of the planned three stages for the hostage release is supposed to occur Sunday, when the guerrillas have said they will set free three Colombian police officers and one soldier. The names of those to be released is not publicly known.
The helicopters, bearing Red Cross insignia, will fly next to Villavicencio, where the freed hostages will be welcomed by members of the Colombians for Peace group, which initiated the hostage release.
On Tuesday, the senator's delegation is scheduled to travel to another site designated by the FARC, Colombia's oldest and largest Marxist guerrilla group. FARC is the Spanish acronym for Revolutionary Armed Forces of Colombia.
At that stop, the group is supposed to pick up the governor of the Meta state, Alan Jara, who was abducted in 2001. The delegation then will receive instructions from FARC on how and where to proceed in the third and final leg Wednesday to collect Sigifredo Lopez, a former official in the city of Valle del Cauca kidnapped in 2003.
FARC announced the release on December 21 and designated Cordoba as the coordinator.
Cordoba previously brokered unsuccessful negotiations in 2007.
Many analysts see this unilateral act by the FARC as the first step toward an eventual peace accord with the government of President Alvaro Uribe. Officials are not discounting further hostage releases.
The Colombian government recently has stepped up pressure on the rebels, offering rewards to the guerrillas if they surrender and free their hostages.
Earlier this month, two guerrillas fled their camp deep in the jungles of southern Colombia, bringing along two kidnap victims -- a 14-year-old boy and an adult man. Both had been kidnapped in December.
Guerrillas have escaped with kidnap victims five times in the past couple of months.
The government has said the FARC's military force has been severely compromised in recent months, but authorities still accuse the group of trafficking huge quantities of cocaine to finance its decades-old insurgency.
The government says 3,000 people remain kidnapped in Colombia and the FARC is responsible for 700 of them.
Among the kidnap victims was former presidential candidate Ingrid Betancourt, who was freed in July with three American military contractors and 11 Colombian police and military members.
Security analysts say FARC has about 9,000 to 12,000 armed guerillas and several thousand supporters, mostly in rural areas.
The guerrilla group was established in 1964 as the military wing of the Colombian Communist Party.
The guerrillas operate mostly in Colombia but have carried out extortion, kidnappings and other activities in Venezuela, Panama and Ecuador, according to the Federation of American Scientists Intelligence Resource Program.
Each helicopter used in the latest operation will carry a crew of five and can travel five hours on a tank of fuel, said El Espectador newspaper, citing Gen. Freddy Padilla de Leon, the commander of Colombian military forces.