A ceasefire has taken effect in an Islamic State enclave straddling the Syria-Lebanon border, where the militants have been fighting the Lebanese army on one front and Hezbollah with Syrian troops on the other.
The Lebanese army announced that a ceasefire in its own offensive took effect at 7am but did not mention Syria's side of the frontier.
Hezbollah and the Syrian army declared a ceasefire in their attack against Islamic State in Syria's western Qalamoun region, Hezbollah's al-Manar TV said.
The battle began a week ago when the Lebanese army, and Hezbollah together with Syrian government forces, launched separate but simultaneous assaults.
Both offensives have advanced towards the border from opposite sides. Lebanon and Shi'ite Hezbollah each said they have made gains against the militants, driving them back into a smaller zone in the arid hills on the border.
The Islamic State enclave in the barren mountains marks the last militant foothold along the Syria-Lebanon frontier.
Northeast Lebanon saw one of the worst spillovers of Syria's war into Lebanon in 2014, when Islamic State and other militants briefly overran the border town of Arsal. The fate of nine soldiers that Islamic State took captive then remains unknown.
The Lebanese army said the ceasefire would pave the way for negotiations over the fate of the soldiers.
A military source said Islamic State militants had "succumbed under fire and asked for negotiations. But if any devious intentions appear," the army would press on with its assault near the town of Ras Baalbeck in the northeast.
Talks have begun with mediation by the head of Lebanon's internal security agency, a security source said.