The evacuation of wounded journalists from the Syrian flashpoint city of Homs will most likely take place late on Monday because it is "dangerous" to pull them out Sunday night, the Red Cross said.
"The evacuation will not happen Sunday because it is dangerous to send ambulances at night," said Saleh Dabbakeh, spokesman for the International Committee of the Red Cross in Damascus.
"It will take place most likely on Monday," Dabbakeh said.
A Western diplomat in Damascus said that some "progress" was achieved in negotiations on Sunday, "but it is too late to go and get them because it is dark."
"The negotiations that were suspended on Saturday evening resumed this morning with strong determination to see them succeed," a Western diplomat in Damascus said earlier.
Nearly 12 hours of talks on Saturday to evacuate those urgently in need of treatment from the besieged Homs neighbourhood of Baba Amr - including two wounded Western journalists and the bodies of two others - were unsuccessful.
"The discussion has yielded no concrete result today. Unfortunately, therefore, no emergency evacuation will take place today," ICRC spokesman Saleh Dabbakeh told AFP on Saturday.
A Western diplomat in Damascus said the talks foundered because of "deep mistrust between the two sides" - the Syrian authorities and the opposition.
"This is making the negotiations very arduous," said the diplomat.
A Western journalist involved in Saturday's negotiations said ambulances twice entered Baba Amr, the district in the flashpoint central city that has been pounded by Syrian troops for more than three weeks.
But each time they were blocked by members of the rebel Free Syrian Army.
The female journalist, requesting anonymity, said the FSA refused to allow the evacuations, alleging that the regime had arrested nine people who were evacuated on Friday, claims the ICRC investigated and said afterwards "were totally false."
Dabbakeh confirmed on Friday that the Red Cross and the Red Crescent had evacuated seven Syrians wounded in shelling, as well as 20 sick women and children, from Baba Amr. They were taken to Homs' Al-Amine hospital.
But they were unable to evacuate two wounded Western journalists and the bodies of two of their colleagues killed on Wednesday in a rocket attack.
American reporter Marie Colvin and French photojournalist Remi Ochlik died when a rocket hit a makeshift media centre in Baba Amr.
French reporter Edith Bouvier and British photographer Paul Conroy suffered leg wounds.