In this still image posted on a militant Twitter account, which has been authenticated based on its contents and other AP reporting, a banner bearing a black flag used by the al-Qaida inspired lslamic State of Iraq and the Levant (ISIL) hangs from an overpass in Mosul, Iraq. Arabic on the banner reads, "Ninevah State welcomes you. God is great and thanks to God." (AP Photo/militant source via Twitter)

Tikrit, Iraq - Iraqi army helicopters fired rockets on one of the largest mosques in the city of Tikrit on Friday, local officials and witnesses said.

It was unclear if there were any casualties in the strikes on Tikrit, the hometown of late dictator Saddam Hussein which was overrun by insurgents earlier this week.