Activists say 10 Iraqi peshmerga fighters have entered a northern Syrian border town, the first from among a group of 150 Kurdish troops on their way into the embattled Kobani.

Kobani-based activist Musrafa Bani says 10 fighters entered the town. He says the rest will follow gradually on Thursday because the border crossing point has been targeted by Islamic State fighters.

The Britain-based Syrian Observatory for Human Rights also says the first group of 10 peshmerga fighters entered Kobani around noon through the Turkey-Syria border crossing.

The mission of the peshmerga troops is to help Kurdish fighters inside Kobani try to break a siege by Islamic State militants.

The peshmerga fighters' push into Kobani followed heavy overnight clashes as Islamic State fighters unsuccessfully tried to capture the border crossing point.