The so-called Syrian Democratic Forces, a US-backed alliance of mostly Kurdish and Arab militants, says it has launched an operation aimed at pushing Daesh out of Raqqah, the Takfiri terror group’s main stronghold in northern Syria.

Talal Sillo, a SDF spokesman, said the operation had begun the “great leap” towards Raqqah in coordination with the US-led coalition purportedly fighting Daesh in Syria and neighboring Iraq.

“We declare today the beginning of the great battle to liberate the city of Raqqa, the alleged capital of terrorism and terrorists,” Sillo told a news conference held in northern Syria. “Morale is high and military readiness to implement the military plan is complete.”

They have been advancing towards the city since last November, and have just forced their way into the city near the Turkish border.

The country’s official Syrian Arab News Agency said civilians had started to flee the city in boats via the Euphrates River ahead of the SDF push.

It also said as many as 12 people, including women and children, had been killed on Monday night in airstrikes by the US-led coalition, which has been pounding alleged Daesh targets in Syria since 2014 without succeeding in eliminating the group.

Daesh seized Raqqa earlier that year, when it started its campaign of bloodshed and destruction against Syria.

The Britain-based so-called Syrian Observatory for Human Rights said 21 people had been killed in the Monday night airstrikes. It said they were likely carried out by the coalition.

Syria has steadfastly objected to the US-led operations as Washington did not seek Damascus’ approval in launching the offensive.

Meanwhile, warplanes belonging to Russia, which has been helping Syria in its counterterrorism operations since 2015, have been reportedly targeting the Daesh terrorists trying to flee Raqqah.

The United States has also been overseeing and sourcing a constant flow of arms and other supplies to Syrian militants, including those of the SDF, which is against the Damascus government.