Twin explosions in a government-controlled neighbourhood of Syria's Homs city killed at least 16 people and wounded scores more on Saturday, a group monitoring the war and state media said, in an attack claimed by Islamic State.

The blasts come days after the government extended its control of the western city with the implementation of a truce deal in Waer, the last insurgent-held area of Homs. Some fighters and civilians have left Waer, and aid has been allowed in.

Waer is located on the western side of the city's outskirts.

A vehicle bomb detonated close to a hospital in the mainly Alawite neighbourhood of al-Zahra in the east of Homs city, the Syrian Observatory for Human Rights monitoring group said.

In a statement posted online, Islamic State described it as a suicide car bomb attack in the centre of Zahra district.

The second large blast, originally suspected to have been a bomb, appeared to have come from an exploding gas canister and hit people who had come to tend to victims of the first explosion in the densely-populated neighbourhood, state media said.

State television had earlier described the attack as "two large terrorist explosions". News agency SANA said the vehicle bomb had been packed with 150 kg of explosives. It published a photo of two men carrying a woman away from burning wreckage.

Footage on state television showed a chaotic scene, with black smoke rising above twisted metal debris. People stumbled over the rubble as they tried to ferry people away from the site.