The extremist organization has unleashed waves of suicide bombers and other attacks in the escalated push to seize government-held areas in the city of Deir al-Zour, according to monitoring groups. An estimated 200,000 people in those areas are quickly running out of food and medicine after a year of blockade by the group, with the United Nations expressing concern about possible deaths due to starvation.

The city’s fall would mark an effective end to the Assad government’s control of the vast expanses of eastern Syria, an area that is now mostly divided between Kurdish forces and the Islamic State. It would also deal a symbolic but important blow to Russia’s military campaign in Syria, which has helped Assad’s forces regain momentum against rebels in the western part of the country but has yet to decisively turn the tide of the war…

The Islamic State’s escalating attacks on Deir al-Zour are a show of force “about reversing setbacks” in parts of Syria and Iraq where the group has been losing territory to U.S.-backed opponents, said Emile Hokayem, a Middle East analyst at the London-based International Institute for Strategic Studies.