Updated | Islamic State car bombs kill dozens in Syria amid talks of truce

At least 46 people were killed, including dozens of civilians, after twin car bomb blasts hit Syria's Homs on Sunday in one of the deadliest attacks of its kind in the city in five years of civil war, the Britain-based Syrian Observatory for Human Rights said.

The Islamic State has since claimed responsibility for the double suicide bombing in the city centre's Zahra district.

Homs is largely under government control and has regularly been targeted in bomb attacks. Sunday’s attacks came a day after the government advances against Islamic State.

#SYRIA#IslamicState Claims Responsibility For Double Suicide Bombing In #Homs. #TerrorMonitor

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A bomb attack claimed by Islamic State last month in Homs in the west of the country killed at least 24 people as government forces took back some Islamic State-held villages in Aleppo province in the north.

Syria’s state news agency SANA said Sunday’s twin car bombing happened near the entrance to the city’s al-Arman neighbourhood, killing at least 45 people and wounded more than 100.

Footage from pro-Damascus television channels showed charred corpses buried among rubble, damage to shop fronts and debris littering a wide area. Many cars were on fire, sending out plumes of black smoke. Wounded people walked around dazed.

State television quoted the governor of Homs as saying at least 25 people had been killed.

The twin bombing – the second most deadly of its kind in Homs since 2011, and the deadliest for almost a year and a half – came on day US secretary of state John Kerry said a “provisional agreement” had been reached on a ceasefire to end the Syrian conflict.

Kerry said the US and Russia planned to reach out to the various sides of the conflict and said that even though details to enforcement still needed to be resolved, the international community was "closer to a ceasefire today than we have been".

On Saturday, a number of Syrian opposition groups declared that they agree to the "possibility" of a temporary truce if President Bashar al-Assad's government and its allies respect several conditions, including halting fire.

On his part, Assad said he is ready for a truce, only if rebels and international backers such as Turkey do not exploit a lull in fighting.

But amid continued discussions on a possible ceasefire raged on, violence rages on unabated across the country, despite a Friday deadline for cessation of hostilities.

Peace talks were suspended almost immediately earlier this month as Syrian government forces and their allies, backed by Russian air strikes, intensified assaults against insurgents in Aleppo province.

The fighting in Syria started as an unarmed uprising against Assad in March 2011, but has since expanded into a full-on conflict that has killed more than 260,000 people, according to UN estimates.

The latest fighting in the north of the country has displaced tens of thousands of people, many of whom headed for the Turkish border. The exodus added to more than 11 million already displaced by the conflict.