A US-backed Kurdish-Arab alliance is advancing against ISIS in the key town of Tabqa near the extremist bastion of Raqqa in northern Syria, a monitor said Sunday.
The Syrian Democratic Forces now control at least 40 percent of the town of Tabqa, and more than half of its heart, the Old City, the Syrian Observatory for Human Rights monitor said.
Observatory director Rami Abdel Rahman said fighting was continuing in the town on Sunday morning.
The SDF entered Tabqa on Monday as part of their offensive against Raqqa, ISIS's de facto Syrian capital.
Supported by US-led coalition air strikes and special forces advisers, the SDF surrounded Tabqa in early April.
The town sits on a strategic supply route about 55 kilometers (34 miles) west of Raqqa, and served as an important ISIS command base, housing the group's main prison.
It is also adjacent to the Tabqa dam, another important strategic prize which remains under ISIS control.
The assault on Tabqa began in late March when SDF forces and their US-led coalition allies were airlifted behind ISIS lines.
The city was home to around 240,000 residents before 2011, and more than 80,000 people have fled to it from other parts of the country.
ISIS still controls three neighborhoods in Tabqa where tousnds of people have been trappe by the radical group, Muhab Nasser told Zaman al Wasl.
ISIS has put up fierce resistance, including using weaponized drones, a tactic the group perfected in neighboring Iraq.
The group is also fighting street-to-street and using suicide attackers and car bombs to slow the SDF's advance, according to the Observatory.
The assault on Raqqa, dubbed "Wrath of the Euphrates," was launched in November and has seen SDF fighters capture large swathes of countryside around the city.
Meanwhile, at least 352 civilians have been killed in U.S.-led strikes against Islamic State targets in Iraq and Syria since the operation began in 2014, the U.S. military said in a statement on Sunday.
The Combined Joint Task Force, in its monthly assessment of civilian casualties from the U.S. coalition's operations against the militant group, said it was still assessing 42 reports of civilian deaths.
It added that 45 civilians were killed between November 2016 and March 2017. It reported 80 civilian deaths from August 2014 to the present that had not previously been announced. The report included 26 deaths from three separate strikes in March.
The military's official tally is far below those of other outside groups. Monitoring group Airwars said more than 3,000 civilians have been killed by coalition air strikes.
Included in Sunday's tally were 14 civilians killed by a strike in March that set off a secondary explosion, as well as 10 civilians who were killed in a strike on Islamic State headquarters the same month.
"We regret the unintentional loss of civilian lives ... and express our deepest sympathies to the families and others affected by these strikes," the Pentagon said in a statement.
More than 465,000 people have been killed in Syria since the country's war began with anti-regime protests in March 2011
