An evacuation of wounded people from three areas in Syria failed to go ahead as planned on Friday but talks continued between the warring parties, sources on both sides of the negotiations said.
A ceasefire between the Syrian army and the Lebanese group Hezbollah on the one side, and Syrian insurgents on the other, came into effect in the town of Zabadani and the Shi'ite Muslim villages of Kefraya and al-Foua on Thursday.
As part of the process, the parties were supposed to begin evacuating the wounded on Friday but unspecified "complications" had so far got in the way, the sources said.
Rami Abdulrahman, who runs the Syrian Observatory for Human Rights monitoring group, also said he had no reports that the wounded were being evacuated by nightfall on Friday.
Talks continued over Zabadani, close to the Lebanese border, and the two villages in the northwest of the country. The negotiations have been led on the rebel side by insurgent Sunni Islamist group Ahrar al-Sham.
The sides agreed on Thursday to extend a ceasefire in the three locations in western Syria, which are away from the main strongholds of Islamic State.
Zabadani has been the focus of an offensive by Hezbollah and the Syrian army against insurgent groups. The area is important to President Bashar Assad because it is close to the capital Damascus and the Lebanese border.
Insurgent groups had been attacking the two villages in the northwestern province of Idlib, an area bordering Turkey that is mostly rebel-controlled after advances against the military this year.