Four hostages held by Colombian left-wing Farc rebels have been released, in a deal brokered by Venezuelan President Hugo Chavez.
The four had a tearful reunion with relatives after being released in the Colombian jungle to Venezuelan envoys.
The Farc says it will not free more hostages until Colombia creates a demilitarised zone for talks.
One of the remaining and most prominent hostages, Ingrid Betancourt, is said by the freed hostages to be very ill.
The hostages, all former members of Congress, are Luis Eladio Perez, Gloria Polanco, Orlando Beltran and Jorge Gechem.
The four were handed over to Venezuelan and Colombian politicians and Red Cross personnel, who had arrived in the jungle on two helicopters to collect them.
Video footage showed the hostages appearing, raising their hands in the air and embracing officials sent to pick them up.
The helicopters took the hostages back to Venezuela, where they were transferred onto private planes for the flight on to Caracas where they met relatives.
Among those waiting in Venezuela's capital was Mr Gechem's wife Lucy, who was emotional when she heard the news.
"I don't know what I am going to say to him, because it is going to be such a happy moment," she told local radio. "I always waited for him and I always fought for him."
After meeting the freed hostages at the presidential palace, Mr Chavez made what he called an appeal "from the heart" to the Farc's leader to move Ms Betancourt to a safe location.
"Move her to a base closer to you while we continue working to pave the way for her definitive release," he said.
Mr Perez said Ms Betancourt, a former presidential candidate who holds dual Colombian-French nationality, had been very badly treated by her captors and was in poor condition.
"It hurts my soul, she is very bad, very, very sick. She is physically and morally exhausted."
It was a tearful reunion in the Venezuelan capital, Caracas
The latest releases follow the freeing last month of two women, Clara Rojas and Consuelo Gonzalez, which Mr Chavez also helped to broker.
These developments have raised hopes that more hostages might be released.
But Mr Perez said Ingrid Betancourt is convinced she will be the last to be freed.
He also urged US politicians to increase the pressure for the release of the three American defence contractors, saying he had a clear message for President George W Bush and the US presidential candidates.
"Please don't leave these Americans in exile in the Colombian jungle."
French Foreign Minister Bernard Kouchner said Wednesday's release was a "powerful encouragement" in the task of freeing the remaining captives.
US state department spokesman Tom Casey welcomed the move, but said it was "reprehensible" that the Farc was continuing to hold hostages.
Pressure for concessions
The rebels, who have long wanted to exchange their high-profile hostages for hundreds of jailed guerrillas, repeated their demand that a demilitarised zone be created where talks can take place on a prisoner exchange.
Gloria Polanco: Former congresswoman, 42, kidnapped in 2001
Luis Eladio Perez: Former senator, 50, kidnapped in 2001
Orlando Beltran: Former congressman, 50, kidnapped in 2001
Jorge Gechem: Former congressman, 57, kidnapped in 2002
Colombian President Alvaro Uribe, who has tense relations with his Venezuelan counterpart, thanked Mr Chavez for his help and reiterated his call for all hostages to be freed.
Mr Uribe has maintained a firm stance against the Farc, which is regarded as a terrorist group by the US and the European Union.
Colombia was involved in a fight against "kidnapping and terrorism", Mr Uribe said, but the nation was "always ready for forgiveness and reconciliation".
The BBC's Jeremy McDermott in Medellin says that with the release, the pressure on Mr Uribe to make concessions to the Farc will increase.
But Colombian Defence Minister Juan Manuel Santos said on Wednesday that the Farc was using its calls for dialogue to gain political space and discredit the government.
Farc rebels are also thought to be holding several hundred other hostages, many of whom were taken for ransom to help fund rebel operations.