Iraqi security forces on Tuesday retook a town next to the militant-held city of Tikrit as they pressed their offensive against Islamic State militants, two military officials said, while the town’s mayor hopes it can become a launchpad for a larger attack.

A Reuters photographer reported seeing dozens of families, who had earlier fled Alam to escape ISIS, returning to the town, celebrating and slaughtering sheep in sacrifice to honor the Iraqi forces.

"I announce officially that the town is under the total control of security forces, the Hashid Shaabi (Popular Mobilisation) units and local tribal fighters," local mayor Laith al-Jubouri told Reuters. "We rejoice in this victory and we want al-Alam to be the launchpad for the liberation of Tikrit and Mosul.”

The Iraqi forces entered Alam early in the morning and hours later gained full control of the town adjacent to Tikrit, the two Iraqi officials said, speaking on condition of anonymity because they were not authorized to talk to reporters.

The battle for Saddam Hussein's hometown is a key test for the Iraqi forces as they struggle to win back some of the Islamic State group's biggest strongholds in Iraq.

Iraqi forces and supporting militias now control towns to the north and south of Tikrit along the Tigris river valley, and security officials say the assault of the city could begin as early as Wednesday, according to Reuters.

If Iraqi forces are able to retake Tikrit, it would add momentum in its campaign to recapture Mosul, the largest city under control by ISIS.

The Islamic State, aware of the advancements, has sent reinforcements to Tikrit. Farther north, the self-proclaimed caliphate came under attack Monday from Kurdish forces around the oil-rich-city of Kirkuk, Reuters reports.

Ahmed al-Karim, the Salahuddin provincial council chief, told The Associated Press that progress of the campaign to reclaim Tikrit had been slow due to roadside bombs and sniper attacks.

Tikrit, Salahuddin's provincial capital that lies about 80 miles north of Baghdad, fell to the Islamic State group last summer, along with Iraq's second largest city, Mosul, and other areas in the country's Sunni heartland.

The offensive to wrest Tikrit from ISIS has received significant assistance from Iranian military advisers who are guiding Iraq's Shiite militias on the battlefield. U.S.-led coalition forces have said they are not providing aerial support for this particular mission because the Iraqis have not requested it.

Before Alam, the offensive succeeded in clawing back a few villages and towns, most notably Dawr, south of Tikrit. Among those directing operations is Iranian Gen. Ghasem Soleimani, commander of the powerful Revolutionary Guard's Quds Force. The overt Iranian role and the prominence of Shiite militias in the campaign have raised fears of possible sectarian cleansing should Tikrit, an overwhelmingly Sunni city, fall to the government troops.

Meanwhile, in neighboring Syria, activists said Tuesday that more than 70 prisoners escaped from an Islamic State jail in a town held by the militant group. The militants then went house to house and set up checkpoints around the northern town of Al-Bab, searching for those who fled.

The prisoners took the opportunity to escape when clashes erupted between rival militant groups, said Bari Abdelatif, an activist from al-Bab who is now based in Turkey.

"There are checkpoints everywhere," Abdelatif said of the situation in the town. He said he was contact with residents and added that IS fighters were driving through town streets and calling on people over loudspeakers to hand over any prisoners they were hiding.

The Britain-based Syrian Observatory for Human Rights and Abdelatif said those who fled included Kurdish fighters who were captured by the Islamic State group in recent months. The Observatory said the IS extremists were able to recapture some of those who fled but did not provide details or numbers.

Along with a third of Iraq, the Islamic State last year also captured a third of Syria. In the past months, the group has been defeated in some areas, including the Syrian border town of Kobani and several surrounding villages.

U.S. military officials have that said a coordinated military mission to retake Mosul will likely begin in April or May and involve up to 25,000 Iraqi troops. But the Americans have cautioned that if the Iraqis are not ready, the offensive could be delayed.

Gen. Martin Dempsey, chairman of the U.S. Joint Chiefs of Staff, said while on a visit to the region on Monday that he is "a bit concerned" about whether the international coalition fighting the Islamic State is sustainable for the longer-term challenge of confronting extremists elsewhere.

Dempsey said that in military terms the campaign against ISIS is "on path." But he put equal emphasis on the importance of sustaining the coalition for the longer term. Shiite dominance in Baghdad has upset predominantly Sunni countries like Saudi Arabia and the United Arab Emirates.

The Associated Press contributed to this report.