"Today our forces headed to Raqqa," after they successfully launched operations from the town of Ein Issa in Girespi, said a source from the SDF.
He added that US-led coalition warplanes were taking part in the operation.
"Our forces will be advancing to the villages of Fatse Big, Fatse Small and Tishi, in order to clear them of ISIS militants first," the source said.
He added that the main target is to liberate Raqqa from ISIS, "as has been demanded by the people of the city several times."
ISIS has reportedly laid a myriad of booby traps and bombs around Raqqa, in anticipation of an offensive.
The assault comes as Iraqi forces were reportedly moving closer to the town of Fallujah west of Baghdad on Tuesday, following an offensive that began on Sunday. Fallujah is the first city that fell to ISIS in June 2014.
ISIS declared its caliphate in Raqqa on June, 29, 2014. Three months later, the US-led coalition carried out its very first airstrikes on the city.
Raqqa is located on the north bank of the Euphrates River, about 160 kilometers east of Aleppo.
Video of SDF forces advancing to Raqqa.
