A number of personnel at a U.S. Marine Corps base on the Japanese island of Okinawa have been diagnosed with the coronavirus, officials say.

The Marines first reported the cases at Camp Butler on Thursday, without disclosing exactly how many had tested positive.

“The individuals that have tested positive have been moved into isolation,” Marine Corps Installations Pacific said in a statement.

U.S. military officials also said a temporary shelter-in-place was issued for nearby Camp Hansen “to allow health professionals to facilitate contact tracing and cleaning teams.”

“These measures are put in place to ensure the safety and well-being of our forces, families, and our Okinawa neighbors,” the Marines said.

On Friday, Marine Forces Japan also issued new coronavirus prevention rules for its personnel there.

For now, personnel will no longer be allowed to eat at restaurants off-base or use non-military public transport, among other restrictions.