The US military has attacked Islamic State positions in the besieged northern Iraqi town of Amerli and airdropped humanitarian aid to civilians trapped there, the Pentagon has said, Al Jazeera reported.
US aircraft delivered over a hundred bundles of emergency supplies and more aid was dropped from British, French and Australian planes, officials said on Saturday.
Iraqi army and Kurdish forces closed in on Islamic State fighters on Saturday in a push to break the Sunni fighters' siege of Amerli, which has been surrounded by the fighters for more than two months.
US jets and drones have also attacked the Islamic State group's positions near Iraq's Mosul Dam.
In the previous weeks, the US forces have conducted airstrikes in support of Iraqi and Kurdish forces on the ground, fighting against the Islamic State, which controls large areas in Syria and Iraq.
Commenting on the airstrikes on Amerli, John Kirby, the US department of defence spokesman, said on Sunday that President Barack Obama authorised the "limited" military operation to prevent an Islamic State attack on the town and to enable an aid drop to those in the town.
In Amerli, thousands of Shia Turkmen have been cut off from food and water for nearly two months besieged by Islamic State fighters. Residents, who are in danger because of their faith and their resistance to the armed group, have vowed to kill themselves rather than risk capture by the group.
Kirby said the aid came at the request of the Iraqi government and that the US military conducted the raids to support the aid delivery, the AP news agency reported.
The strikes come as Iraq launched a major operation to liberate the besieged town, with support from armed Shia Muslims. The AFP news agency reported that Kurdish peshmerga were also involved in the operation.
Al Jazeera's Jane Arraf, reporting from Baghdad, said on Saturday that any airstrikes by the US around Amerli would widen its mandate in Iraq of protecting US personnel and critical Iraqi infrastructure.
She said men in the town had taken up arms against the Islamic State and had been resisting the group for weeks.
"They're backed by Shia militia members who have been flown into the town by Iraqi helicopters - then around that you've got the circle of Islamic State fighters and around that from both sides you have the militias and the Iraqi army."
"If the operation fails the fear is it could lead to even more sectarian violence."
Strikes near Mosul dam
Regarding the airstrikes near Mosul dam, the US deaprtment of defence said that the US warplanes and armed drones destroyed an Islamic State armed vehicle, a fighting position and weapons, and damaged a building near the dam.
Separately on Saturday, a suicide bomber driving a car packed with explosives killed at least 13 people in a town just south of Baghdad.
The Islamic State group, an al-Qaeda off-shoot formerly known as ISIL, overran most of Sunni Arab areas of Iraq after seizing the northern city of Mosul on June 10, and have proclaimed a caliphate straddling the border with Syria, where they also control vast swaths of territory.
Backed by US air power, Kurdish forces recaptured the strategic dam nearly two weeks ago.
The Turkmen, ethnically Turkish, are Iraq's third largest ethnic group after Arabs and Kurds.