One of the two American service members missing in Morocco jumped into the water to try to save the other missing soldier, defense officials told CBS News on Monday.  

Search and rescue efforts were still underway as of Monday after the two U.S. Army soldiers went missing in the waters of the Atlantic Ocean off Morocco's southern coast over the weekend. The soldiers were part of an annual training exercise known as African Lion, although the incident is not believed to be related to the exercise.

According to a preliminary report, a group of service members was on a hike to watch the sunset when a soldier fell into the water. A defense official previously told CBS News the soldiers were last seen near ocean cliffs near the Cap Draa Training Area.

When the first soldier fell into the water, the nearby service members attempted a rescue by forming a human chain with their belts, but were unsuccessful, the officials said. Another soldier then jumped in to save the service member, who was known not to be able to swim, but the would-be rescuer was immediately hit by a wave, the report indicates. 

Both soldiers were having trouble getting back to shore, so a third jumped in. That third soldier wasn't able to save the other two but was able to make it back safely on their own, the officials said.

Multiple aircraft, drones, divers and vessels have been searching along Morocco's southern coast for the last three days for the two missing U.S. soldiers.

African Lion is the largest annual joint military exercise led by AFRICOM, one of the U.S. Department of Defense's 11 unified combatant commands. It brings together thousands of troops from the United States, African partner nations and NATO allies to train for modern warfare across land, air, sea, cyber and space domains.   

The soldiers were stationed at a base along with more than 7,000 service members from over 30 countries for the annual exercises.