The U.S., Morocco and other countries participating in the African Lion exercise have launched a search and rescue operation, AFRICOM said.

“The incident remains under investigation and the search is ongoing,” it said in a statement.

The incident happened on Saturday at about 9 p.m., the Moroccan military said, near the Cap Draa Training Area near Tan Tan, close to the Atlantic Ocean. The terrain is mountainous, a mix of desert and semidesert plains.

The war games exercise started in April and runs across four countries, including Tunisia, Ghana and Senegal. It is scheduled to end in early May.

The command did not state what unit or branch of the military the missing service members belong to. The Associated Press has requested clarification.

The exercise began in Tunisia with active-duty members of different branches of the U.S. military, including the National Guard, Army Reserve, Air Force, and the Marine Corps.

In all, over 7,000 personnel from more than 30 nations are participating across the four host countries.

African Lion, which has been running since 2004, is the largest U.S. annual joint military exercise on the continent and usually features high-ranking military officials from the U.S. and its top African allies.

U.S. military officials have said the annual multinational engagement serves as a venue for strengthening regional security cooperation and refining the readiness of participating forces for global crises.

In 2012, two U.S. Marines were killed and two others injured during a helicopter crash in Morocco’s southern city of Agadir while taking part in African Lion.

Morocco is a major ally of the United States in a troubled region. Since 2020, military officers disillusioned with their governments’ records of stemming violence have overthrown democratically elected governments in Mali, Burkina Faso and Niger and began distancing themselves from Western powers.