Eight U.S. Navy personnel assigned to the USS Abraham Lincoln carrier strike group have attempted suicide since the beginning of its extended deployment connected to the war in Iran, according to a letter from Acting Navy Secretary Hung Cao obtained by  Newsmen.

The incidents occurred over roughly 10 months since the carrier strike group began its deployment, Cao said in the letter sent Tuesday to Sen. Kirsten Gillibrand, a member of the Senate Armed Services Committee.

The disclosure came in response to questions from Gillibrand about the health and well-being of sailors serving aboard the carrier and other vessels operating with the strike group.

“Since the beginning of LINCOLN’s deployment, there have been a total of eight suicide attempts across the strike group,” Cao wrote.

According to the letter, the figure includes personnel serving aboard the USS Abraham Lincoln as well as sailors assigned to the carrier air wing, strike group and destroyer squadron staffs, escorting destroyers and embarked aviation squadrons.

The disclosure raises concerns about the mental health and well-being of sailors during the carrier strike group’s prolonged deployment, which has been extended amid U.S. military operations related to the conflict with Iran.