A ceasefire in a Syrian town near the Lebanese border and in two villages to the north has broken down after renewed heavy shelling, the Syrian Observatory for Human Rights monitoring group said on Saturday.
The truce between the Syrian army and the Lebanese group Hezbollah on the one side, and Syrian insurgents on the other, came into effect on Thursday in the western town of Zabadani and the Shi'ite Muslim villages of Kefraya and al-Foua in the northwest.
Local ceasefires in Syria's four-year conflict have tended to be fragile, and UN attempts to forge larger truces in other parts of the country, notably in the northern city of Aleppo, have come to nothing.
The ceasefire in the three areas had been extended late on Friday but had collapsed by the morning, said Rami Abdulrahman, who runs the Britain-based Observatory.
Insurgents fired around 200 shells into areas in and around Kefraya and al-Foua early on Saturday, and Syrian warplanes carried out raids elsewhere in the province, he said.
Sources on both sides said talks were continuing despite the ceasefire breach. The negotiations on the rebel side have been led by the Islamist Ahrar al-Sham group.
The sides had discussed evacuating the wounded from the three areas under the ceasefire but so far none have been transported out, the Observatory said.
Zabadani has been at the center an offensive by Hezbollah and the Syrian army against insurgent groups. The area is important to the Syrian government because of its proximity to the capital Damascus and the Lebanese border.
The two villages, in the province of Idlib, have been under attack by insurgents. The area borders Turkey and is mostly rebel-controlled after advances against the military this year.