Rockets fired by jihadists Sunday killed six civilians and wounded nine others in the government-held northern city of Aleppo, state news agency SANA reported.
It said two neighbourhoods were struck in the "terrorist rocket attack" and that one rocket hit the municipal building in the city, which the regime retook full control of at the end of 2016.
The Britain-based Syrian Observatory for Human Rights war monitor confirmed the toll, with its head Rami Abdel Rahman saying the number of dead could rise because some of the wounded were in serious condition.
"Jihadists west of Aleppo have been targeting the city since the morning," Abdel Rahman said.
Pro-government newspaper Al-Watan said on its Telegram messaging app that the "army has been responding to terrorist attacks... with salvos of rockets".
It was not immediately clear who fired the rockets that hit Aleppo.
Fighters of Syria's former Al-Qaeda affiliate Hayat Tahrir al-Sham (HTS) are deployed in the neighbouring province of Idlib and nearby regions including the western Aleppo countryside.
Smaller jihadist and Islamist groups are also deployed in those areas.
Russian and regime aircraft have ramped up strikes on Idlib since the end of April, killing nearly 600 civilians.
HTS fighters and other combatants have responded with attacks on Syrian government troops in the region, including in the northern sliver of Hama province, which also neighbours Aleppo.
Since Russia intervened on the government's side in 2015 the regime has notched up a series of victories against opposition fighters and jihadists who overran large parts of Syrian in the first years of the war.
Government forces have retaken all areas once held by the rebels except for Idlib province and parts of the neighbouring provinces of Hama, Aleppo and Latakia.
Idlib and its surrounding areas are supposed to be protected from a massive regime offensive by a September 2018 deal between Russia and rebel backer Turkey.
A buffer zone planned under that accord was never fully implemented, and the region has seen an uptick in violence.
Syria's war has killed more than 370,000 people and displaced millions since it started in 2011 with a brutal crackdown on anti-government protests.