Jim Michaels

USA TODAY

BAGHDAD — U.S. airstrikes targeted Islamic State militants Saturday near the strategically important Mosul dam, which fell into the extremists' hands earlier this month.

The attack marks an apparent expansion in the U.S. military's role in Iraq, where it has been hammering Islamic State fighters with airstrikes for more than a week in an attempt to roll back some of the gains of militants and protect Irbil, the capital of the Kurdish region in northern Iraq.

U.S. Central Command said Saturday's total of nine airstrikes — which included a mix of fighter and remotely piloted aircraft — were to support humanitarian efforts and protect U.S. personnel and facilities. The strikes destroyed or damaged several armed vehicles, it said in a statement.

Kurdish military said the dam remains in the hands of militants but fighting in the area has intensified.

The developments came as at least 80 Yazidis in a small village in northern Iraq were executed by Muslim extremists after they refused demands to convert to Islam, Kurdish officials and Yazidi activists said Saturday.

Kurdish officials said Islamist militants ordered Yazidis in the besieged village of Kocho to convert to Islam or die. They had the village surrounded for more than a week.

Khoder Dolmi, a Yazidi activist, said the Islamic State sent a delegation to the village a week ago, demanding they convert. They were initially given three days to comply but were allowed an extra two days after a local tribal leader intervened, he said.

They still refused.

On Friday, militants entered the town and separated the men from the women and girls.

"They lined up the men and shot them in the head in front of their families," Dolmi said. He said 200 men were killed, though most Kurdish officials put the number at about 80.

He said the women and girls were imprisoned. The militants, who belong to the Islamic State, consider anyone who doesn't share their extreme view of Islam as infidels.

The Yazidis, scattered in small villages in northern Iraq, have suffered at the hands of militants who now control large swaths of territory in Iraq.

The alleged massacre at Kocho suggests the plight of the religious minority is not over despite a U.S. humanitarian effort to save thousands of Yazidis who fled the village of Sinjar and escaped to a mountain.

U.S. aircraft dropped food and water to the refugees and airstrikes kept militants from attacking them. President Obama on Thursday said the U.S. effort broke the siege of Mount Sinjar and saved lives.

Contributing: The Associated Press