Kurdish forces took control Thursday of the disputed Iraqi oil hub of Kirkuk to protect it against jihadists who have seized large chunks of neighbouring territory, officials said.

Iraqi Kurds want to incorporate Kirkuk province into their autonomous region, a move Baghdad strongly opposes in a bitter, long-running dispute with them.

"We tightened our control of Kirkuk city and are awaiting orders to move toward the areas that are controlled by ISIL," Brigadier General Shirko Rauf of the Kurdish peshmerga security forces told AFP.

He was referring to jihadist Islamic State of Iraq and the Levant, which has spearheaded a major offensive this week that has overrun all of one province and parts of two others, one of which is Kirkuk.

Meanwhile, Kirkuk Governor Najm al-Din Karim said Kurdish peshmerga forces were filling in gaps left by Iraqi soldiers who withdrew from their positions in the province.

"Army forces are no longer present, as happened in Mosul and Salaheddin," Karim said.