A suicide bomber killed at least five people as Islamic State fighters re-entered the Syrian Kurdish battleground city of Kobani.

Activists says that a suicide bomb was detonated in the area near the border crossing with Turkey.

Syrian Observatory for Human Rights director Rami Abdel Rahman added: "Fierce clashes erupted afterwards in the centre of the town and there are bodies lying in the streets."

The fighting was still raging on Thursday morning.

IS battled for four months to take Kobani but Kurdish fighters backed by US-led air strikes took control of the border town in January.

Since then the Kurdish People's Protection Units (YPG) have advanced from Kobani in Aleppo province to neighbouring Raqa province.

In the past few days they have captured the strategic border town of Tal Abyad and pushed towards Raqa city in the Euphrates valley to the south.