(CNN) -- Colombian rebels are prepared to release 10 hostages on Monday and Wednesday, officials said.
The Revolutionary Armed Forces of Colombia, or FARC, had announced the impending release of the 10 -- the last of the government hostages they hold -- in February, and since then has been negotiating details of the release.
Monday and Wednesday have been designated as the two days for the hostage releases, said Jordi Raich, head of the International Committee of the Red Cross delegation.
"We know the families and the loved ones of all these people have been waiting for so long: 12, 13, 14 years, and now is a very difficult moment, a moment of nervousness," he said. "Our main message to them is to be patient for two or three more days because this is an extremely complex operation where many people are involved and the key point of it all is to do it in a safe way, security is an extremely important to us."
Brazilian helicopters will arrive in Colombia on Sunday and will be used in the operation, he said.
Support from the Red Cross will not end with the reuniting of the hostages with their families, Raich said.
Psychological support, both for the families and the hostages who have been captive in the jungle for more than a decade, is very important, he said.
The story doesn't end with the hostages' release because "after so many years of separation, there is still a lot to do to help them overcome the trauma of this period of time that they have not been together, without news, to help them reintegrating into society," he said.
The leftist rebels have been at war with the Colombian government since the 1960s. While severely weakened in recent years, the group has continued to carry out kidnappings and attack security forces.
In February, the FARC announced that it was releasing the hostages, and would stop kidnapping civilians for money.
It did not address the fate of its civilian captives, nor did the group renounce kidnapping for political purposes.
CNN's Luisa Calad and journalist Toby Muse contributed to this report.