U.S.-Led Coalition Airstrike Kills 21 Civilians as Forces Breach ISIS Capital Raqqa, Monitors Say

Raqqa offensive
American army vehicles drive north of Manbij city, in Aleppo Governorate, Syria, March 9. The U.S.-led coalition is accelerating its campaign to liberate Raqqa. Reuters/Rodi Said

Updated ¦A Syrian opposition monitoring group has claimed that a U.S.-led coalition airstrike killed 21 civilians as they attempted to flee the eastern Syrian city of Raqqa, which has been held by the Islamic State militant group (ISIS) for more than three years.

The U.K.-based Syrian Observatory for Human Rights (SOHR), which cites a wide network of activists and sources on the ground in Syria, said coalition jets bombed the civilians as they attempted to escape the jihadi bastion in a dinghy across the Euphrates River.

SOHR's director Rami Abdelrahman told AFP news agency that the route had been used in the past by ISIS fighters fleeing the city. In an emailed statement to Newsweek, a coalition spokesperson said: "The coalition takes all allegations of civilian casualties seriously and will assess these allegations, as we do all allegations of possible civilian casualties."

"Coalition forces comply with the law of armed conflict and take all reasonable precautions during the planning and execution of airstrikes to reduce the risk of harm to civilians. Our goal is always for zero civilian casualties."

It added that more information would be avaliable in its monthly civilian casualty report.

The allegations came as the Kurdish-Arab alliance that the U.S. led coalition is supporting with air power and advisers on the ground announced a "great battle" to capture Raqqa on Tuesday and breached the city limits of Raqqa for the first time.

"Our forces entered the city of Raqqa from the eastern district of Al-Meshleb," SDF commander Rojda Felat told AFP.

The Syrian Democratic Forces (SDF) have been recapturing territory, cutting off access points and preparing for the battle for central Raqqa during a seven-month advance through the province of the same name.

Read more: What to know about the coming battle for Raqqa, the ISIS capital

Raqqa was the first city ISIS captured before it went on to announce its self-proclaimed caliphate that straddles the Iraqi-Syrian border and includes part of Mosul, in northern Iraq.

The coalition's commanding general Steve Townsend said in a statement Tuesday that the offensive would bring an end to the idea ISIS can hold onto territory.

"It's hard to convince new recruits that ISIS is a winning cause when they just lost their twin 'capitals' in both Iraq and Syria," he said.

"We all saw the heinous attack in Manchester, England. ISIS threatens all of our nations, not just Iraq and Syria, but in our own homelands as well. This cannot stand."

Since January 2014, ISIS militants have controlled the eastern Syrian bastion in Deir Ezzor Province, which served as a hub for operations planning, financing, and the detention of hostages. It became central to the group's state project, which leader Abu Bakr al-Baghdadi would formally announce in a speech at Mosul's Great Mosque in July later that year.

As the effects of the U.S.-led coalition's air campaign, which began in September 2014, wore on the group's operations, top leaders and foreign fighters headed for the surrounding countryside or to Iraq in the east. Now, between 3,000 and 3,500 ISIS fighters remain in the city, the coalition said in March.

This story was updated on 6 June to include a statement from coalition forces.