American troops in Iraq had their first actual battle with ISIS troops after the Islamist militants tried to overrun a base, an encounter that left the ISIS troops decimated and in retreat.

The attack took place near the Ein al-Asad base, which includes close to 100 U.S. military advisers. The U.S. troops, armed with “light and medium weapons,” and were able to inflict casualties against the ISIS fighters, forcing them to retreat, Shafaq News reported. The American troops were also aided by fighter jets, which directed air strikes against the ISIS troops that “silenced their heavy sources of fire.”

“US forces intervened because of ISIS started to come near the base, which they are stationed in so out of self-defense,” said Sheikh Mahmud Nimrawi, a prominent tribal leader.

The incident was the first time that American troops clashed with ISIS forces on the ground in Iraq. For several weeks, the United States has led a series of air strikes against ISIS positions in Iraq and Syria, ones aimed at crippling the militant group’s ability to move about the country and coordinate attacks.

ISIS has responded by calling on members to strike out against American interests in the United States and Canada, and also executing Western hostages. Rebels are now reportedly trying to sell the body of American journalist James Foley for a reported $1 million.

Militants are reportedly offering a DNA sample from Foley’s body to prove its authenticity.

“They ask for $1 million, and they will send DNA to Turkey, but they want the money first. They will not give the DNA without the money,” a former Syrian rebel reportedly told BuzzFeed.

The man claimed to be motivated not by greed or a quest for fame, but by a desire to help the mourning Foley family “find closure,” and deemed his outreach as part of a “humanity case.”

The U.S. forces attacked by ISIS in Iraq were part of a small group that remained in the country to offer support and training to tribal fighters.