Daesh militants launched their biggest attack in months on the Assad regime-held areas of the Syrian city of Deir Al-Zor today, killing dozens of civilians and regime troops, a war monitor said.
At least six large explosions rocked the city since dawn as the militants clashed with the regime's army and allied Iran-sponsored Shia jihadists, the British-based Syrian Observatory for Human Rights (SOHR) reported.
Syrian regime warplanes hit back against Daesh positions, it added.
A military media unit run by Damascus's ally and Iran proxy Hezbollah said the army was repelling attacks by the hardline militant group along several frontlines, including east of the city and around its military airport.
Syrian state television said Daesh shelling killed three people and wounded nine in regime-held districts.
Daesh controls most of Deir Al-Zor province, which borders Iraq, including more than half the city, and has besieged the remaining regime-held areas of the city for nearly two years.
The Syrian regime of President Bashar Al-Assad and its Russian ally have made regular aid drops into the encircled zone, where about 200,000 people live, lacking food and medicine.
Deir Al-Zor province links Daesh's de facto capital in the Syrian city of Raqqa with territory controlled by the militant group in Iraq.
Since last November, a US-backed offensive largely led by Kurdish leftist militants has been making steady progress in an attempt to recapture Raqqa and force Daesh into a retreat in its Syrian heartland.