Damascus, June 25 (IANS): Islamic State (IS) militants on Thursday launched a major offensive on northern Syria's Hasaka city.

According to the Syrian Observatory for Human Rights, intense clashes broke out between the Syrian government forces and IS militants in the southern districts of Hasaka on Thursday, Xinhua news agency reported.

"IS militants detonated at least one booby-trapped vehicle at a government troops' checkpoint at the western entrance of Hasaka," the Observatory said, adding that "the militants reached the Sport City street, adjacent to the Central Prison and the Criminal Intelligence Branch, after storming districts Nashweh and Sharia districts".

At least 30 government troops and 20 IS militants were killed during Thursday's battles.

Meanwhile, Syria's state-run Al-Ekhbariya TV said, "government troops are fighting intense battles against IS militants in Nashweh neighbourhood, which houses many displaced families from the eastern province of Deir al-Zour, which is an IS stronghold."

It said the IS are committing crimes against the residents of that neighbourhood.

Earlier this week, the IS staged several car bombings in Hasaka, leaving dozens of people wounded and killed.

It has been the second attack on Hasaka in June.

The last attack was foiled by government forces.