Syria crisis: IS makes deadly return to Kobane
They detonated car bombs and launched an assault. Kurdish media say at least 50 civilians have been killed, including 20 in a nearby village.
IS has recently suffered a string of defeats to Kurdish forces.
But in another attack on Thursday, it seized parts of the key north-eastern city of Hassakeh.
Key events in battle for Kobane
The apparent two-pronged IS offensive came as Kurdish fighters from the Popular Protection Units (YPG) cut a major supply line for IS near Raqqa.
Raqqa is the de facto capital of the caliphate whose creation IS announced a year ago after it captured large swathes of northern and western Iraq.
BBC