Iraq has reportedly received the first consignment of fighter jets ordered by the country from Russia to help fight an offensive by Sunni militants.
According to the BBC, Iraqi security officials said five second-hand Sukhoi attack aircraft would enter service within a few days, and that more were on their way.
The militants have taken control over most of north and west areas following a series of attacks over the past three weeks.
Thousands of Iraqi troops launched an offensive on Sunni militants in Tikrit from four directions with tanks and air power on Saturday.
The state television said the governor's HQ had been recaptured and 60 fighters from the ISIS militant group have been killed.
The report said that the ISIS has been successfully cleared from the city.
While some of the militant commanders were among the 60 killed, the others have reportedly fled.