Street fighting is raging in the Syrian-Turkish border town of Kobane with Isis making rapid advances.
Civilians in Kobane are fleeing the area after Isis hoisted its flags atop buildings and hills fuelling tensions.
The jihadist fighters stormed the Syrian town with the help of tanks and artillery following which street fighting broke out with Kurdish defenders.
"They're fighting inside the city. Hundreds of civilians have left. Islamic State controls three neighbourhoods on the eastern side of Kobane. They are trying to enter the town from the southwest as well," said Rami Abdurrahman, chief of Britain-based Syrian Observatory for Human Rights, which keeps track of all developments in the country through various sources.
Kurdish forces have told residents of the area to leave fearing escalation in the fighting.
"Military officials asked civilians to evacuate - they declared Kobane a military area. ISIL advanced to the eastern side. There were fierce clashes in the streets," spokesperson Mustafa Bali told AFP.
According to analysts, if the Sunni militants are successful in their attempt to capture the town, it would enable them to exercise control along the entire stretch of the border between Syriaand Turkey.
Local reports say more than 2,000 Isis fighters are taking part in the ongoing offensive. Isis has been trying to seize the town for the past three weeks but the Turkish side insists they have not reached the city centre.
"If they enter Kobane, it will be a graveyard for us and for them. We will not let them enter Kobane as long as we live. We either win or die. We will resist to the end," Esmat al-Sheikh, chief of the Kobane Defence Authority told Turkey's Hurriyet Daily News.