A fourth U.S. service member has died from injuries sustained during the U.S. operation in Iran, U.S. Central Command said on Monday.

The service member had been seriously wounded during Iran’s initial attacks and later succumbed to those injuries, the command said in a statement.

The latest death brings the total number of American soldiers who have died in the conflict with Iran to four.

Central Command also confirmed that another injured American soldier, wounded the previous day, has died.

U.S. military officials have said that one more injured service member remains in critical condition.