Six Kurdish fighters were killed on Monday when ISIS attacked the holding complex in Raqqa, the group's former de facto capital in Syria, in a bid to free fellow militants.
The Syrian Democratic Forces said the offensive — Operation Al Jazeera Thunderbolt — aimed to “eliminate” ISIS from areas that had been “the source of the recent terrorist attacks”.
The SDF said the operation was being carried out alongside the US-backed anti-ISIS coalition, although there was no immediate confirmation from the international force that it was taking part.
The statement said that, in addition to the thwarted Raqqa attack, ISIS fighters had recently carried out eight assaults in the northern Syrian areas of Deir Ezzor, Hasakah and Al Hol camp for displaced people, which houses militants' family members.
Referencing recent Turkish air strikes on Kurdish forces in north-east Syria, the SDF said ISIS was trying to “take advantage” of the situation by “carrying out more terrorist attacks”.
After conquering large parts of Iraq and Syria in 2014, ISIS saw its so-called caliphate collapse three years later, but it continues to launch attacks through sleeper cells in both countries.
The SDF has spearheaded the fight against ISIS in Syria and drove the group from its last stronghold in the country in 2019.
US Central Command, which oversees American military operations in the Middle East, said on Thursday that it has carried out 108 “partnered” operations against ISIS in Syria during 2022, along with 14 unilateral operations, leading to the arrest of 215 militants and the deaths of 466 others.
Agencies contributed to this report