Twin blasts hit a Syrian military bus in Damascus on Wednesday, killing 14 people, state media reported, the deadliest such attack in the city in more than four years.

The Syrian state news agency SANA, citing a military source, said that "around 6:45 this morning (0345 GMT) and as the military bus was passing on the President Bridge it was subjected to a terrorist attack by twin explosive devices that were previously attached to the bus, resulting in 14 martyrs and a number of wounded."  

The agency earlier reported that the army's engineering units had dismantled a third bomb planted in the same area.

So far, there has been no claim of responsibility.

Images on Syrian television showed charred parts of the bombed bus and rescuers putting out a resulting blaze as well as removing body parts from inside the vehicle.

The dead were mostly Syrian soldiers, according to a Syrian military source, who spoke on condition of anonymity as he was not authorized to talk to the media.

The bus usually seats 30 people, the source added.

The Syrian Observatory for Human Rights, a war monitor, reported earlier that the blast had killed 14 people and that the toll was likely to increase.

"The dead were all military personnel including soldiers and officers," Rami Abdel-Rahman, head of the British-based observatory, told dpa.

Residents in Damascus told dpa the twin blasts caused loud bangs, which echoed across the city and triggered panic.

Residents added that Syrian security forces had imposed tight  measures around the area where the blast took place and started checking the identity cards of passers-by in the area.

Blasts targeting army personnel and civilians in Damascus have decreased since forces loyal to Syrian President Bashar al-Assad took control of rebel-held areas on the outskirts of the capital.

Wednesday's attack is the worst to have hit Damaascus since March 15, 2017, when more than 40 civilians died after a suicide bomber blew up his explosive belt in central Damascus, the observatory said.

Elsewhere in the war-torn country, shelling by Syrian government forces on a rebel-held area on Wednesday killed at least 13 civilians including three children, the observatory said.

The shelling took place in the area of Ariha in Syria's north-western province of Idlib as children were on their way to school, local activists said.

At least 24 others were also injured in the shelling.

Activists in the area posted online pictures showing bodies lying in the streets.

Idlib is the last rebel stronghold in Syria. Russian-supported Syrian government forces launched a major offensive in the region in 2019, raising UN concerns over the safety of the civilians there. 

Russia and Turkey agreed on a ceasefire for the long-disputed area in March of last year, but in recent months Syrian government forces backed by their Russian allies have resumed heavy shelling on some areas in Idlib.  

Russia and Iran back al-Assad, while Turkey has been supporting opposition forces since an uprising started against him in 2011. 

dpa