BEIRUT: A newly formed US-backed Syrian rebel alliance on Saturday launched an offensive against Daesh in the northeast province of Hasaka, a day after the United States said it would send special forces to advise insurgents fighting the jihadists.

It was the first declared operation by the Democratic Forces of Syria, which joins together a US-backed Kurdish militia and several Syrian Arab rebel groups, since it announced its formation earlier this month.

World powers and regional rivals are convening in Vienna to seek a solution to the four-year conflict in Syria that has escalated since Russia intervened a month ago with an intense air campaign.

The decision by US President Barack Obama to send special forces to Syria is strictly focused on fighting Daesh and does not signify the United States is entering the civil war there, US Secretary of State John Kerry said.

“President Obama has made a very strong and forceful and simple decision entirely in keeping with his originally stated policy that we must defeat and destroy Daesh,” Kerry said.

“It is not a decision to enter into Syria’s civil war. It is not an action focused on (Syrian President Bashar) Assad, it focused exclusively on Daesh and in augmenting our ability to rapidly attack Daesh,” Kerry said in Kyrgyzstan’s capital, Bishkek.

Fighting in Hasaka had begun after midnight, a spokesman for the alliance said. A group monitoring the war reported fighting and coalition air strikes in the area.

A video posted earlier on Youtube announced the offensive in southern Hasaka, and showed several dozen men in fatigues standing outdoors with yellow flags and banners carrying the name of the Democratic Forces of Syria in Arabic and Kurdish.

The campaign would “continue until all occupied areas in Hasaka are freed from Daesh,” a spokesman for the alliance’s general command said in the video. He urged residents to stay away from Daesh-controlled areas of Hasaka.

The United States’ decision to station ground troops in Syria comes after it dropped ammunition to rebel groups in northern Syria several weeks ago.

Washington’s strategy in Syria has shifted from trying to train fighters outside the country to supplying groups headed by US-vetted commanders.

The Britain-based Syrian Observatory for Human Rights, which monitors developments on the ground, said fighting was raging on Saturday near Al-Hawl, a town close to the Iraqi border, accompanied by coalition air strikes.

Hasaka province borders Iraq and territory there that is a crucial stronghold for Islamic State.

Meanwhile, international medical charity Medecins Sans Frontieres said on Saturday that at least 70 people had been killed in a missile attack on a marketplace near Damascus the day before.