A senior Iraqi general on Wednesday called on Iraqis fighting for ISIS in Mosul to surrender as a wide-scale operation to retake the militant-held city entered its third day.

Lt Gen Talib Shaghati told reporters at a military base on Tuesday that up to 6,000 ISIS fighters are inside the city. He did not say how many of them are foreigners.

ISIS captured Mosul, Iraq's second largest city, in a lightning advance in the summer of 2014. The extremist group has suffered a string of defeats over the past year, and Mosul is its last major urban bastion in Iraq.