U.S. Marines have been deployed to northern Syria to help in the fight to retake the city of Raqqa from Islamic State militants.
The Washington Post, which first reported the deployment, says the arrival of the artillery battery is a significant escalation in the use of U.S. conventional forces in Syria. There has been no official announcement, but military officials have confirmed the deployment to other news agencies. A U.S. Army artillery unit is already in place in the area.
Marines also have been dispatched to the town of Manbij, located about 138 kilometers northwest of Raqqa, the Islamic State group's self-declared capital of its supposed caliphate. As many as 4,000 IS fighters are believed to be in Raqqa.
The U.S. Defense Department has described the mission in Manbij as one to "reassure and deter" local parties from attacking one another.
Until now, the United States has deliberately limited its ground troops in Syria to around 500 Special Operations forces supporting the U.S.-backed Syrian Democratic Forces, an alliance of Arab and Kurdish forces fighting IS. Military officials say the extra troops are heading to Manbij to prevent rival factions from turning on each other.
Meanwhile, a Syrian activist group says at least 14 people, including eight children, have been killed in airstrikes on a northern Syrian village held by Islamic State.
The British-based Syrian Observatory for Human Rights says it believes U.S.-led coalition jets targeted the village of al-Matab, located west of Raqqa. As many as 4,000 IS fighters are believed to be in Raqqa.