Thirteen people have been killed in clashes in Kurdish-held eastern Syria between US-backed fighters and members of an affiliated group whose leader was arrested two days ago, a war monitor reported Tuesday.
"Ten local fighters and three members of the Syrian Democratic Forces (SDF) were killed" in the clashes which began on Monday in several villages in the east of Deir Ezzor province, the Syrian Observatory for Human Rights said.
The US-backed, Kurdish-led SDF spearheaded the battle that dislodged ISIS group militants from the last scraps of territory they controlled in Syria in 2019.
The affiliated group, the Deir Ezzor Military Council, is led by Ahmad al-Khabil, also known as Abu Khawla, who was arrested in the city of Hasakah late Sunday, the Observatory said.
The move sparked tensions that deteriorated into clashes after gunmen attacked SDF positions, added the Britain-based Observatory, which has a network of sources inside Syria.
The charges against Khabil were not immediately clear, however the Observatory and an activist told AFP he was known to have been involved in smuggling and had amassed considerable wealth over the years.
The Deir Ezzor Military Council, one of several Arab groups affiliated with the SDF, is responsible for security in parts of Arab-majority Deir Ezzor province.
"What's happening today is a settling of scores," said Omar Abu Layla, an activist who heads the DeirEzzor24 media platform.
"Corrupt commanders felt they were in danger after Abu Khawla was arrested and have tried to turn it into a tribal and Arab issue in order to protect themselves," he added, warning that the unrest could "negatively impact the region".
The SDF has not commented, but said in a statement that it had launched "an operation to bolster security" on Monday in Deir Ezzor province against ISIS and "criminals... involved in drug trafficking and benefiting from arms smuggling".
The operation was continuing "in order to arrest those involved in criminal activity", added the statement.
Syria's war has killed more than half a million people since it broke out in 2011, escalating into a deadly conflict that pulled in foreign powers and militants insurgents.