The Pentagon announced on Sunday that more American troops will be deployed to Iraq, following an Islamic State rocket attack on a Marine position in which Staff Sgt. Louis F. Cardin of California became the second U.S. soldier killed by the Islamic State.

“The undisclosed number of troops will be a detachment from the 26th Marine Expeditionary Unit and will support Iraqi forces and international ground operations,” Fox News reports, noting that this would seem to be difficult to square with President Obama’s “no boots on the ground in Iraq” promises.

“The 26th MEU is deployed to maintain regional security in the Persian Gulf, Red Sea, Arabian Sea and parts of the Indian Ocean,” stated the Pentagon, according to Fox News. “Members of the unit are aboard three U.S. Navy amphibious assault ships: the USS Kearsarge, the amphibious transport dock ship USS Arlington and the dock-landing ship USS Oak Hill.”

CNN quotes Pentagon press secretary Peter Cook saying Staff Sgt. Cardin was “providing force protection fire support at a recently established coalition fire base near Makhmur in northern Iraq.”

The base had only been operational for a few days before ISIS attacked, and its existence had not yet been disclosed to the American public, which does not know hundreds of Marines are setting up firebases and artillery positions along the ISIS front lines. They have been told the increased troop commitment to fight the Islamic State consists mostly of special operators flying around in helicopters, and trainers helping the Iraqi Army get into shape for the big push against the ISIS stronghold of Mosul.

CNN cites a U.S. official speculating that ISIS was drawn to the site by the Marines test-firing their howitzers and an Iraqi general who says his own forces come under daily rocket fire from the Islamic State in the area.

An official who spoke to Fox News described the hit on the Marine position as a “lucky strike by ISIS” and said that in addition to Cardin’s death, “less than five” others were injured. However, the Marine Times reports eight other Marines were injured in the attack.

USNI News says Cardin, 27, was a native of Temecula, California. He joined the Marine Corps in 2006, and was stationed at Camp Lejeune.

“His awards include the Navy and Marine Corps Achievement medal, three Marine Corps Good Conduct medals, three Afghanistan Campaign medals, Iraq Campaign medal, National Defense Service medal, Presidential Unit Citation-Navy, Navy Unit Commendation Medal, NATO Medal-ISAF Afghanistan, Global War on Terrorism Medal, and three Sea Service Deployment ribbons,” said a statement from the II Marine Expeditionary Force.

“Staff Sergeant Cardin’s service and his many important contributions will long be remembered by his fellow Marines, his teammates at United States Central Command, and a grateful nation. Our gratitude and heartfelt condolences go out to this young man’s family and friends.” said U.S. Army General Lloyd Austin, commander of CENTCOM, in a statement released on Sunday.