Iraqi forces were gearing up to move further into Tikrit on Friday, but said they were adopting a strategy of caution as they approached the city from all sides.

"Islamic State" (IS) played down news that it had sustained losses and was moving out of Tikrit, stating that losses it had made so far were an ordinary part of warfare.

"The State remains steadfast ... and is becoming stronger and continues to be victorious," IS spokesman Abu Mohammed al-Adnani said, describing gains claimed by its enemies as "fake."

"It is a mere taking back of a few villages in a war that is about attack and retreat," he said, in the group's first official reaction to the developments.

Government commanders said they hoped to consolidate the hold they had on the city, driving out the remaining pockets of resistance from IS fighters.

"Now we are moving to the second phase of our plan," Defense Minister Khaled al-Obeidi told reporters in Salaheddin province on Thursday. "We are very keen for our losses to be as low as possible. Time is on our side, we have the initiative."

Tactics take a toll

There has been little in the way of figures provided so far about the fighting, but the government troops have sustained losses, with dozens of bodies reported to have been driven to Baghdad and the holy city of Najaf. Guerilla tactics such as suicide attacks, car bombings, booby traps and snipers said to be doing the most damage to the Iraqi and Shiite forces.

As well as strategic value, Tikrit also has major symbolic significance and there are fears the Shiite militia might seek revenge against residents of the chiefly Sunni city.

The hometown of executed dictator Saddam Hussein, the city houses remnants of Hussein's Baath party, which is accused of collaborating with IS.

The US-based Institute for the Study of War claims that local residents are suspected of involvement in the apparent mass execution of some 1,200 Shiite recruits captured last year by IS.

rc/sms (AFP, AP, dpa, Reuters)