Beirut-The Syrian opposition has warned that escalated conflicts between the Syrian regime and Kurdish militias in Hasakah might lead to civil war.

Syrian regime jets pounded U.S.-backed Kurdish forces in northeastern Syria for a second day on Friday, even after the U.S.-led coalition scrambled jets to protect its military advisers working on the ground, as announced by the Pentagon.

“This was done as a measure to protect coalition forces,” Pentagon spokesman Captain Jeff Davis said.

Since Wednesday, clashes between the two forces have rocked the city, leaving 23 civilians – including nine children – and 16 combatants dead, according to the Syrian Observatory for Human Rights.

The Observatory said thousands of inhabitants had begun to flee Hasakeh, where bread was running out and electricity supplies have been cut.

A regime source in the city told Agence France Presse that the air strikes were “a message to the Kurds that they should stop this sort of demand that constitutes an affront to national sovereignty.”

The Russian Ministry of Defense announced on Thursday that they agreed over the 48 hour ceasefire since it would allow humanitarian aid to reach the besieged areas of the Aleppo Governorate. U.N.’s special envoy to Syria Staffan de Mistura hailed the Russian decision.

Political researcher Sulaiman al-Yusuf told Asharq Al-Awsat newspaper that it is not the first time that Syria witnesses such an escalation in conflicts and that the Syrian Democratic Forces (SDF) attempt every now and then to expand in northern Syria and diminish the regime’s control there.

“The Syrian regime wanted to send a clear message to the SDF that its power in Hasakah is limited and the regime airstrikes were carried out to serve this purpose. A civil war between Kurds and regime is unlikely because they have mutual interests,” added Yusuf.