At least 20 people were killed on Monday in a twin car bombing in the eastern Syrian city of Hasakah, Syrian state TV said.
Syrian Observatory for Human Rights (SOHR), reported that one of the car bombings occurred in the northern part of the city and the other in its centre. The Britain-based SOHR said that the car bombings killed several Kurdish militia members.
More than 50 were also wounded due to the attack, the SOHR said, the casualties were not yet identified as being civilians or militants.
The first bombing took place at a check point of the Kurdish militia called Asaish. The other car bombing was executed in Mahatat Al Kitar, a train station close to a base belonging to local Kurdish militias, including "People's National Defense militia" who are pro-Syrian regime.
This area has seen fierce confrontations between ISIS, Syrian regime forces, pro-regime militias and the Peoples Protection Units (YPG) which is the armed unit of the Democratic Union Party (PYD), the Syrian affiliate of the PKK.
PKK is recognised as a terrorist organisation by the EU, NATO, and as well as Turkey.
Independent Syrian media claims that ISIS is behind the massive car bombings.
The local militias later closed off a number of roads, after receiving confirmed reports about five more car bombs scattered around the city.
Local news website, Qasioun said, the bombing at the train station was due to the detonation of explosives fixed to a water tank. According to Qasioun , a third explosion took place in Tal Hajar neighbourhood, which is under the control of the YPG. The reason for the explosion was not known, nor the amount of casualties.
Meanwhile, intense clashes took place on Monday morning between ISIS and the YPG in the outskirts of Abdu Aziz mountains western countryside of Hasakah. Moreover, Syrian regime forces launched artillery shells at the positions of the clashes, in an attempt to counter ISIS' attack on the strategic mountain.
Hasakah province, which regime has maintained control of during the conflict in Syria, until recent offensive by ISIS, is divided into separated zones. The province of Hasakah has a strategic position, since it borders territory held by ISIS in Iraq.
ISIS had launched an attack on the city of Hasakah and took control of the southern districts in June, and has forced tens of thousands to flee the city. But later the YPG pushed ISIS out and took control of the territories again.
Battles between ISIS and YPG
On June 21, the YPG - backed by the US-led coalition air strikes - captured the border town of Tal Abyad, which lies near the Turkish border from ISIS. Capturing Tal Abyad means that the YPG effectively controls some 400 km of the Syrian-Turkish border.
In January 2015, the ISIS-held border town of Kobani was captured by the YPG - backed by the US-led coalition air strikes - after a siege that lasted for four months against ISIS.
ISIS’ loss of the Turkish-Syrian border town of Kobani, also known as Ayn al Arab, was seen as a significant defeat regarding the amount of extensive military resources they invested in to capture the isolated town on the border with Turkey.
The YPG now controls the border from Syria’s northeastern corner to the town of Jarabulus, which is under ISIS control.
ISIS currently holds control over large swaths of territory, stretching eastward from the outskirts of Aleppo, Syria’s largest city, to western Iraq.
Dozens of ISIS militants, government troops and pro-government militias had been killed since the beginning of ISIS’ offensive in June.
The war in Syria started in 2011 in the form of anti-government peaceful demonstrations, but descended into a civil war between five main factions - the regime, the opposition, Al Qaeda-affiliated Nusra Front, ISIS, and the Kurdish People's Protection Units (YPG) militia.