The truce agreement was a result of talks between Russia, Assad’s main ally, and Turkey, a leading backer of the rebels.
The British-based Syrian Observatory for Human Rights has confirmed 815 people have been killed.
Turkey said it would allow Iraqi Kurdish fighters to reinforce fellow Kurds in the Syrian town of Kobani.
The coalition had conducted 21 attacks on ISIS militants near the Syrian town of Kobani.
The Islamic State wants to take Kobani in order to strengthen its grip on the border area.
Rami Abdulrahman said it wasn't clear which countries carried out the strikes.
Western officials believe the Syrian army has been under growing strain since ISIS staged advances.
The UN Security Council authorised the movement of UN aid through four border crossings in July.
Reports say fighting erupted on the Golan Heights on Monday between government forces and rebels.
The dead are said to number as many as 250 soldiers.
The Pentagon are preparing options for an assault on ISIS fighters.
ISIS stormed Tabqa air base near Raqqa city on Sunday after days of fighting with the army.
The UN has confirmed Peter Theo Curtis was released to its peacekeeping force.
A UN report shows around 5,000 to 6,000 people are being killed monthly.
The group's advance in Syria has accelerated since it seized control of Mosul in June.
The bombs were placed in two tunnels running under the city.
An election affirmed his grip on power more than three years into Syria’s civil war.
The Western-backed National Coalition elected Hadi al-Bahra as its new president.
