Hundreds of recruits at Marine Corps Recruit Depot San Diego are suffering from “diarrheal symptoms” following a bacterial outbreak at the facility, officials said.

Medical personnel are treating 302 patients of the more than 5,500 recruits in training at MCRD-San Diego, The San Diego Union-Tribune reported.

Officials discovered the illness in recruits at both the depot and Edson Range, Camp Pendleton, California, a location used for field training by MCRD-San Diego recruits, according to the article.

Marines have yet to identify the source of the contagion but commanders have quarantined sick recruits and ordered increased hand-washing and a review of proper sanitation in all training areas.

“Our immediate focus is identifying, isolating and treating recruits who present symptoms,” said Brig. Gen. William Jurney, the commander of both the depot and the Corps’ Western Recruiting Region, in a written statement provided to the newspaper. “We are working to identify the cause of the sickness, making sure our affected recruits can return to training as soon as possible and continuing training for recruits not influenced.”

Medical staff that service the depot have increased barracks, dining facility and common area inspections in the wake of the illness outbreak, according to the report.

If a recruit’s graduation date is delayed due to the illness, family members will be notified, officials said.