BEIRUT -- The latest on the conflict in Syria, where a fragile cease-fire has begun but scattered violence and clashes continue (all times local):
Syria's state-run news agency says armed groups have fired several shells on residential areas in the capital in the first breach of a cease-fire.
SANA says the shells were fired Saturday by "terrorist groups" entrenched in Jobar and Douma, both opposition-held suburbs of Damascus. It was the first time the Syrian government has accused rebel groups breaching the cease-fire agreement.
The fragile cease-fire went into effect at midnight but scattered violence and clashes continue.
Opposition groups say they have recorded numerous violations by government forces across the country.
A Syrian rebel commander says his fighters have registered numerous government cease-fire violations and warns they could lead to the collapse of the agreement.
Lt. Col. Fares al-Bayoush, commander of the 1,300-strong Fursan al-Haq Brigade, a US-backed rebel faction, tells The Associated Press that his group and others affiliated with the mainstream Free Syrian Army are so far abiding by the truce.
He says continued government breaches however will force rebel factions to retaliate.
He adds however that the cease-fire brokered by the US and Russia which went into effect at midnight has sharply reduced government attacks across northern Syria where his group is based.
A top military official says Russia has grounded its warplanes in Syria to help secure a cease-fire brokered by Moscow and Washington.
"The Russian Federation has completely stopped attacks in the 'green zone', that is to say those areas and armed units that have sent to us requests for cease-fire," Maj. Gen. Sergei Rudskoy said Saturday at a briefing in Moscow.
He said 17 opposition units have contacted the Russian military to adhere to the truce that became effective at midnight Friday.
Members of the Islamic State group have stormed a northern border town that was captured months ago by Kurdish fighters, according to a Syrian rebel official.
Talal Sillo, a spokesman for the predominantly Kurdish Syria Democratic Forces, said Saturday that the IS fighters have attacked the town of Tal Abyad. The fighting began after midnight Friday and was still ongoing, Sillo said. Tal Abyad that has been held by Kurdish fighters since July.
The Britain-based Syrian Observatory for Human Rights also confirmed the fighting in Tal Abyad.
The Aamaq news agency, which is affiliated with the extremist group, reported that IS fighters launched a "surprise attack" on several areas in northern Raqqa province, where Tal Abyad is located. But the report did not provide further details.
Sillo told The Associated Press that SDF fighters "will finish the operation today."
Syria's state news agency says a car bomb has exploded on the edge of a government-held central town, killing two and wounding several others.
No one claimed responsibility for Saturday's blast on the eastern entrance of the town of Salamiyeh which came hours after a cease-fire brokered by Russia and the US went into effect.
The Islamic State group has claimed responsibility for several bombings in Syria in recent weeks.
Opposition activists in different parts of Syria said the situation has been "cautiously calm" since the truce went into effect at midnight Friday.
The truce does not include either IS or al-Qaida's branch in Syria, known as the Nusra Front.
The Syrian government and 97 rebel and militant groups said they will abide by the cease-fire.