The two crew members were rescued by a sea drone in the first such operation ever carried out by the U.S. military, officials told CBS News.

“The mission is a proportional response to unjustified Iranian aggression,” U.S. Central Command says.

U.S. Central Command confirmed that two crew members were rescued after a U.S. Army AH-64 Apache attack helicopter crashed near Oman on June 8 during a patrol mission. According to CENTCOM, both personnel were recovered within two hours and were reported to be in stable condition after receiving medical attention.

The US military has used Apaches, along with MQ-9 Reaper drones and F/A-18 and F-35 fighter jets, as part of Central Command's operation challenging Iran's effective closure of the Strait of Hormuz to most commercial traffic.

Once the crew was found, they were transferred safely using the autonomous vessel. They were then lifted from the water by a rescue helicopter. Officials said this is believed to be the first time an autonomous US Navy vessel deployed in the Middle East has been used directly in a rescue mission.

U.S. forces launched a second straight day of air strikes Wednesday in Iran as President Donald Trump presses for a settlement to end a war that has simmered for months. U.S. Central Command announced what it called “self-defense strikes” against multiple targets without providing further details.