Six cases of coronavirus have been confirmed in Texas, according to the Centers for Disease Control.

The patients are being quarantined at Lackland Air Force Base in San Antonio. The first case involves a traveler who returned to the U.S. on a State Department-chartered flight from Wuhan City, China the epi center of the outbreak. The others were passengers from the Diamond Princess cruise ship quarantined in Japan.

The individuals will remain isolated at medical facilities until they test negative for COVID-19, the disease caused by the virus, and are no longer at risk of spreading it, the Texas Department of State Health Services said.

The six cases are the only ones in Texas. Health officials said the risk to the public is low as the patients have been under federal quarantine since their return and have not interacted with the public.

The Texas military base is one of four identified by the Department of Defense as possible housing for quarantined coronavirus patients. The DOD is currently housing 198 people at March Air Reserve Base in California and has “identified housing support” for up to 1,000 additional people.

In addition to Lackland, the other bases tapped as possible quarantine sites are the 168th Regiment, Regional Training Institute in Fort Carson, Colorado; Travis Air Force Base, California; and Marine Corps Air Station Miramar, California.

Coronavirus evacuees not coming to Alabama

Plan to bring coronavirus evacuees to Alabama cancelled by Trump, lawmakers say