Two Iraqi security officials say that government forces have driven out Islamic State militants from the entire oil refinery town of Beiji, north of Baghdad.

The officials say that Iraqi troops on Friday also lifted the Islamic State group's siege of the oil refinery, Iraq's largest.

The officials, reached by phone in Beiji, spoke on condition of anonymity because they were not authorized to talk to media.

Iraqi state TV also reported the "liberation of Beiji," quoting the top army commander there, Gen. Abdul-Wahab al-Saadi.

Islamic State extremists captured Beiji during their summer blitz across north and western Iraq. The Iraqi forces had collapsed in the face of that onslaught but have since partially regrouped and went on the offensive, with Beiji the biggest locality they have recaptured to date.