(CNN) -- Iraqi security and volunteer forces have broken the siege of Amerli and have entered the town, retired Gen. Khaled al-Amerli, an Amerli resident and member of its self-defense force, told CNN on Sunday.
Iraqi state TV also reported that the siege had been broken.
The news prompted a wave of celebrations across the town, which had been besieged by fighters from the terror group ISIS. Residents waved the Iraqi flag and fired celebratory shots into the air, al-Amerli said.
"Today is a day of victory for Iraq and the resilient people of Amerli," the retired general said.
The breakthrough came after the United States said it carried out airstrikes and dropped humanitarian aid in Amerli to protect an ethnic minority that one official said faced the threat of an "imminent massacre." Amerli is home to many of Iraq's Shiite Turkmen.
Australia, France and the UK also participated in the aid drop.
The U.S. military conducted "coordinated airstrikes" against ISIS targets as part of an effort to support the humanitarian operation, Pentagon press secretary Rear Adm. John Kirby said.
Video released by the Iraqi Ministry of Defense was strikingly similar to the scenes of the dire situation faced by the Yazidis, who were trapped on Mount Sinjar by ISIS earlier this month. Dozens of people crowded helicopters, hoping to be rescued. Scores more waited in the scorching summer sun for the arrival of lifesaving supplies.
ISIS fighters had surrounded Amerli, 70 miles north of Baquba, since mid-June. The town's fewer than 20,000 residents have been without power.
"Residents are enduring harsh living conditions with severe food and water shortages, and a complete absence of medical services -- and there are fears of a possible imminent massacre," U.N. High Commissioner for Human Rights Navi Pillay said last week.
ISIS has called the Shiite Turkmen heretics and vowed to push them out.
Turkmen are descendants of a Turkic-speaking, traditionally nomadic people, who share cultural ties with Turkey. There are Sunni and Shiite Turkmen in Iraq, and they account for up to 3% of Iraq's population.
Turkmen have been subjected to violence before at the hands of Sunni extremists.
Sen. John McCain, R-Arizona, is calling on President Barack Obama and his administration to address the threat posed by the Islamic State in Iraq and Syria.
"We have to have a clear strategy dictated by a policy and that policy has to be we have to defeat ISIS, not contain, not stop, but defeat ISIS, because they are a direct threat over time to the United States of America," McCain said Sunday on CBS' "Face the Nation."
McCain was referring to the controversy that erupted last week after the President admitted on Thursday "we don't have a strategy, yet" for airstrikes against ISIS targets in Syria.
Dianne Fienstein, McCain's Senate colleague and chair of the Intelligence Committee Democratic senator, also urged the Obama administration Sunday to devise a strategy for confronting ISIS.
Feinstein said on NBC's "Meet the Press" Sunday that ISIS is one of the most vicious terrorist movements ever.
"I think I've learned one thing about this president, and that is he's very cautious. Maybe in this instance too cautious. I do know that the military, I know that the state department, I know that others have been putting plans together. And so hopefully those plans will coalesce into a strategy that can encourage that coalition."
Iraqi forces under a Shiite-led regime, as well as ethnic Kurdish forces, have been battling ISIS, which this year took over large portions of northern and western Iraq and eastern Syria for what it calls its new caliphate.
Well before ISIS made gains, Iraq was beset for years by sectarian violence, with Sunnis feeling politically marginalized under a Shiite-led government since the U.S.-led ouster of longtime leader Saddam Hussein in 2003.
CNN's Shelby Lin Erdman, Yousuf Basil, Raja Razek, Joshua Berlinger and Chelsea J. Carter contributed to this report.