The U.S. military carried out a new series of airstrikes Sunday against ISIS targets in Iraq, while some 20,000 Yazidi Iraqis who had been trapped on Mount Sinjar were rescued and taken to the Syrian-Iraqi border.
Iraqi Ministry of Human Rights spokesman Kamil Amin told CNN that Kurdish forces were able to break the siege by ISIS and help thousands of stranded Yazidis board trucks, which drove them to the Syrian border town of Hasaka near Iraq. They were then driven north along the Syrian-Iraqi border to Dohuk, a region in northern Iraq's Kurdish region.
In Dohuk, the Kurdish government helped the refugees find shelter, Amin said.
The Yazidis are a target of ISIS, which calls itself the Islamic State and was known as the Islamic State in Iraq and Syria. Yazidis are part of one the world's oldest monotheistic religious minorities. Their religion is considered a pre-Islamic sect that draws from Christianity, Judaism and the ancient monotheistic religion of Zoroastrianism.
Before the rescue operation, there had been from 50,000 to 60,000 Yazidis stranded on the mountain, Amin said, and thousands remain.
Kurdish forces also recaptured two towns from ISIS, a senior Kurdish official said.
"Mahmour and Gweyr are in Kurdish hands," Qubad Talabani, deputy prime minister of the Kurdistan Regional Government, told CNN on Sunday. The Islamist militant group had seized the towns Wednesday on a march toward Irbil.
However, the Kurds lost ground on other fronts.
Kurdish fighters battling ISIS militants lost control of the strategically important Iraqi town of Jalawla, two Kurdish officials and police officials told CNN.
Clashes erupted Sunday morning for control over the predominately Kurdish town that links Kurdish areas to Baghdad, and the Kurdish Pershmerga fighters eventually withdrew from Jalawla.
Last week, President Barack Obama authorized targeted attacks not only to protect Iraqi minorities from ISIS' murderous rampage, but also Americans stationed in the Kurdish regional capital of Irbil.
The U.S. State Department said Sunday that some of its staff have been relocated from the U.S. Consulate General in Irbil. The announcement came as the department issued a travel warning saying that "the ability of the Embassy to respond to situations in which U.S. citizens face difficulty, including arrests, is extremely limited."
The U.S. continued its airstrikes Sunday, and within five hours, it had struck five targets, including armed vehicles and a mortar position, U.S. Central Command said.
The strikes began at 9:15 a.m. local time (2:15 a.m. ET) Sunday, the military said.
A campaign of brutality
ISIS fighters have carried out slaughter in parts of Iraq and Syria, where they claim to have created a caliphate.
The militants have become infamous for their brutality. In Syria, the group put some of its victims' severed heads on poles. In another instance caught on camera, a man appears to be forced to his knees, surrounded by masked militants who identify themselves on video as ISIS members. They force the man at gunpoint to "convert" to Islam, then behead him.
On Sunday, Amin told CNN that it was possible that as many as 500 Yazidis had been killed, and the ministry had also heard reports -- but had not confirmed them -- that some had been buried alive.
"It's difficult to be accurate about these numbers, but initially we have reported 500 Iraqi Yazidis have died from either ISIS direct killings or from starvation and dehydration," Amin told CNN. "We have heard some reports from activists and local journalists that some families were buried alive."
CNN is unable to authenticate reports regarding the Yazidi death toll or the allegation that some were buried alive.
ISIS fighters killed in strikes, Iraq says
Iraqi officials said U.S. airstrikes Saturday killed 16 ISIS fighters. An Iraqi airstrike in Sinjar killed an additional 45 ISIS fighters and injured 60 Friday, Iraq state media reported.
Hundreds of U.S. military personnel are in Iraq, including advisers sent in recently to coordinate local military officials fighting ISIS. Many of them and U.S. consular staff are based in Irbil.
Obama has cautioned that the airstrike campaign will be a "long-term project."
"I don't think we're going to solve this problem in weeks," the President told reporters Saturday.
But he reiterated his vow that no U.S. combat troops will join the fight.
And despite U.S. strikes, ISIS militants reportedly captured Iraq's largest hydroelectric dam, just north of Mosul, the nation's second-largest city.
The militant fighters have been using U.S.-made weapons seized during fighting from the Iraqi army, including M1 Abrams tanks, local officials said.
had been conflicting reports about who controlled the dam on the Tigris River, with heavy fighting under way between ISIS fighters and Kurdish forces, known as peshmerga.
U.S. officials have warned that a failure of the dam would be catastrophic, resulting in flooding all the way to Baghdad.
60 children dead
While fighting rages, the humanitarian crisis on Sinjar Mountain continues. Iraqi security forces have been able to airlift about 100 to 150 people a day off Sinjar Mountain, said Marzio Babille of UNICEF, the United Nations' children's agency. And time is running out for many who cannot reach airdropped supplies.
Dozens, including 60 children, have died on the mountain, where the Yazidis are battling extreme temperatures, hunger and thirst.
Britain and France have said they will join the United States in the airdrops. A British C-130 cargo plane delivered aid to Iraq on Sunday, a Ministry of Defense spokesman said.
UNICEF is urging international actors help open a humanitarian corridor over land -- a safe escape route -- to evacuate the Yazidis.
On Sunday, Pope Francis said he is sending an envoy to Irbil. The envoy will leave Rome on Monday, the Pope said.
On Saturday, three U.S. cargo planes, accompanied by U.S. fighter jets, airdropped 3,804 gallons of fresh drinking water and 16,128 ready-to-eat meals to Yazidis stranded in the mountains, the military said.
CNN's Ashley Fantz and Chelsea J. Carter reported and wrote from Atlanta, and CNN's Barbara Starr reported from Washington. CNN's Ben Brumfield, Mohammed Tawfeeq, Hamdi Alkhshali, Elise Labott, Ivan Watson and Joshua Berlinger contributed to this report.