Iraqis are welcoming the U.S. airlift of emergency aid to thousands of people who fled to the mountains to escape Islamic extremists.

And now, for the first time, U.S. forces are directly targeting the extremist Islamic State group, which controls large areas of Syria and Iraq. The Pentagon says U.S. fighter jets bombed a piece of artillery after it fired near U.S. personnel outside the city of Irbil.

The Pentagon says the militants were using the artillery to shell Kurdish forces defending the city. A spokesman says it's not clear how many militants may have been killed in the strike.

In announcing approval of the new U.S. airstrikes last night, and the delivery of humanitarian aid to besieged religious minorities in northern Iraq, President Barack Obama vowed again not to put U.S. combat troops back on the ground in Iraq.

Also, the spokesman for Iraq's human rights ministry says hundreds of women from the Yazidi religious minority have been taken captive by militants from the Islamic State group.

Kamil Amin says the women are below the age of 35 and some are being held in schools in Iraq's second largest city, Mosul. He said the ministry learned of the captives from their families.

Tens of thousands of Yazidis fled when the Islamic State group earlier this month captured the northern Iraqi town of Sinjar, near the Syrian border. Amin's comments were the first Iraqi government confirmation that some women were being held by the group. The Yazidis practice an ancient religion that the Sunni Muslim radicals consider heretical.