The Iraqi army has reached the centre of the northern city of Beiji, as they continue their effort to break the siege of the Islamic State of Iraq and the Levant (ISIL) on the country's biggest oil refinery nearby. Al Jazeera's Imran Khan reports from Baghdad. Subscribe to our channel http://bit.ly/AJSubscribe Follow us on Twitter https://twitter.com/AJEnglish Find us on Facebook https://www.facebook.com/aljazeera Check our website: http://www.aljazeera.com/