The commander of Iraq's military operations in Salahuddin province says government forces have launched the final phase of an offensive to recapture the Islamic State-held city of Tikrit.

Lt. Gen. Abdul-Wahab al-Saadi tells The Associated Press Thursday that Iraqi troops and special forces have begun moving toward the center of Tikrit, Saddam Hussein's hometown.

The Islamic State group seized the Sunni city last summer during its lightning advance across northern Iraq.

At Iraq's request, the U.S. began airstrikes on Tikrit on Wednesday in support of the stalled ground offensive. Iranian military advisers have been providing significant support since the offensive began on March 2, and Shiite militias have played a prominent role on the battlefield.