On Monday, three Marines were killed by an improvised explosive device detonated near Bagram Air Base in Afghanistan. A number of others were injured in the attack, although the Pentagon hasn’t released an official count related to the incident. The Taliban claimed responsibility for the attack. A statement issued Tuesday by the Operation Resolute Support staff reads,

Three U.S service members were killed in an improvised explosive device attack during a convoy near Bagram Airfield,” it said. “A contractor, who was reported as killed, is alive. The contractor, an Afghan citizen, was initially treated along with other injured civilians, later identified as a contractor and treated at Bagram.”

The three Marines have yet to be identified by the U.S. Department of Defense (DOD), pending notifications of their next of kin. They represent half of all Marine Corps’ duty fatalities thus far this year, following two killed in an AH-1Z Viper helicopter crash in Yuma, Arizona last month and a Marine who died on duty in Washington D.C. in January.

These deaths bring the total count of U.S. service members killed in Afghanistan this year to seven.

Gen. Scott Miller, commanding general of Operation Resolute Support and U.S. forces in Afghanistan, said in a Pentagon statement, ‘We feel and mourn the loss of these Americans with their families and loved ones. They volunteered to protect their country. We will continue our mission.’”

The Taliban claimed it launched the attack by sending a suicide bomber in an explosive-laden vehicle near the base for detonation. This account is not in keeping with official statements made by the DOD, which indicates the explosive was stationary and hidden.

Currently, there are approximately 14,000 U.S. troops deployed to Afghanistan in support of the embattled national government’s efforts to curb Taliban expansion and combat the few remaining pockets of the Islamic State. In 2018, 13 American service members were killed in what was the 17th year of this conflict.

Recently, the United States engaged in preliminary stages of peace talks with the Taliban. Although the terrorists have participated in a dialogue, they continue to mount near daily attacks against Afghan security forces. Thus far, Taliban officials refuse to meet with the formal Afghan government, claiming they’re controlled by U.S. interests.