Two Navy sailors died from COVID-19 complications in the past week, deaths that were revealed as the Pentagon on Wednesday moved to reimpose mask mandates at some of its installations.

Capt. Corby Ropp, 48, of Swansboro, N.C., died July 23 at Duke University Hospital in Durham, N.C., and Navy Reserve Master-at-Arms 1st Class Allen Hillman, 47, of Boise, Idaho, died July 26, according to the Navy.

Ropp was the head of ophthalmology and refractive surgery at the Navy Medicine Readiness and Training Command at Camp Lejeune, N.C., while Hillman was assigned to the Navy Reserve Volunteer Training Unit in Boise.

It is not known if either were vaccinated against the virus.

The two bring the total number of Navy sailor COVID-19 deaths to 10. Across the military, 28 service members have died of the virus, according to the latest Pentagon numbers.

Hillman’s and Ropp’s deaths come as coronavirus infections and hospitalizations are surging in some parts of the country due to the highly contagious delta variant of the virus, with the Centers for Disease Control and Prevention this week recommending that even vaccinated people wear masks in crowded indoor settings in areas where transmission is high.

The increased cases have also caused the White House on Tuesday evening to instruct federal agencies in Washington, D.C., and other areas where there is a high degree of community transmission of COVID-19 to require employees, contractors and visitors to wear masks indoors regardless of their vaccination status.

Following that, the Defense Department released a memo to its personnel, ordering a return to masks in “in areas of substantial or high transmissions.” 

“Deputy Secretary Hicks has directed that all individuals, regardless of vaccination status, wear masks in indoor settings at Department of Defense installations and facilities in areas of substantial or high transmission, as defined by the CDC, to protect against rising COVID-19 cases,” Pentagon spokesman Jamal Brown said in a statement.

The announcement applies to all service members, federal personnel, contractors, and visitors when indoors at all properties owned by the department.

The Air Force is the most vaccinated service, with 81 percent of its force having received both doses of the shot. The Navy comes in second with nearly 80 percent vaccinated, the Army is at 71 percent, while the Marines have the worst numbers at only 57 percent.