In addition to the soldiers killed, five have been seriously injured, writes the US military command CENTCOM. It is not clear when the soldiers were injured or where they have been deployed.
Additional soldiers have suffered minor shrapnel injuries and concussions, according to the military.
Iran has threatened to escalate retaliatory attacks against Israel and US military installations in the region following the killing of the country's supreme leader Ali Khamenei.
"Today we will strike them with a force they have never seen before," wrote Ali Larijani, head of Iran's Supreme Security Council, on X.
He warned countries in Iran's vicinity of upcoming attacks.
"We are not attacking you. But when bases in your countries are used against us, and when the United States carries out operations in the region using these bases as a starting point, we will attack them. The bases are not part of your countries, they belong to the United States."
Explosions in several countries
Since the US and Israel launched their attacks on Iran on Saturday morning, Saudi Arabia, the United Arab Emirates, Qatar, Jordan, Kuwait and Bahrain - all of which host US bases - have reported Iranian missile and drone attacks of varying intensity.
The United Arab Emirates on Sunday condemned an Iranian drone attack on a naval base in Abu Dhabi, which houses French forces, the AFP news agency reported. The attack reportedly resulted in two containers catching fire. No one was reportedly injured in the attack.
Since Saturday, however, a total of three people have been killed and 58 injured in Iranian attacks, according to the country's authorities.
Explosions were also heard in Qatar and Bahrain on Sunday.
Israeli shelter hit
Iran's Revolutionary Guard also said it fired four ballistic missiles at the US aircraft carrier Abraham Lincoln. However, the Pentagon said the ship was not hit in the attack.
Meanwhile, new waves of Iranian rockets are being reported from Israel. Nine people have been killed and around 60 people injured after an Iranian rocket hit a shelter in Beit Shemesh, west of Jerusalem, reported the Israeli newspaper Haaretz.
Several of the victims are said to have been in the shelter, which was not robust enough to withstand a direct hit from a rocket. One death was previously reported from Israel on Saturday.
