U.S. airlifts hundreds of militia fighters to cut off Raqqa

WASHINGTON — Hundreds of Syrian fighters and their U.S. military advisers, backed by U.S. artillery and attack helicopters, have begun a major operation to cut off the western approaches to Raqqa, the city the Islamic State has proclaimed as its capital, officials said Wednesday.

It was the first time that the United States had carried out an air assault in Syria in its campaign against IS, and the mission, which began Tuesday, reflected the leeway the Trump administration has given its commanders to carry out operations without prolonged review in Washington.

In a significant commitment of U.S. forces, U.S. helicopters ferried fighters across enemy lines while Marine Corps howitzers, Army Apache attack helicopters and American warplanes provided firepower for the operation. Army surface-to-surface Himars rockets, which are based in northern Syria, are also part of the mission. American Special Operations forces were advising the Syrian fighters on the ground, although a military spokesman said they were not involved in direct, frontline combat.

The mission represented a new stage in the broader offensive to cut off and seize Raqqa. Its objective was to take control of the Tabqa Dam on the Euphrates River near Lake Assad, the nearby town of Tabqa and a local airfield. An immediate goal was to take the dam intact, but the structure was still under the control of IS, and officials said that the fighting was intense.

“The fighting is raging on as I speak and is expected to last several weeks until the dam, airfield and city are free from ISIS control,” said Col. Joseph E. Scrocca, a spokesman for the U.S.-led command in Baghdad.

As the operation unfolded, Syrian state television and local residents asserted that at least 30 Syrian civilians were killed in an airstrike that hit a school where they had taken shelter in a rural area of Raqqa province on Tuesday. U.S. military officials acknowledged that the United States had been carrying out airstrikes in the area. These officials said they could not confirm the reports of civilian casualties, but would investigate.

As the battle for Raqqa has accelerated, the number of airstrikes has climbed. Col. Scrocca said over the past four months the U.S.-led coalition had conducted more than 300 such strikes around Tabqa and west of Raqqa, and that enemy fighters, fortifications and vehicles had been targeted.