WASHINGTON, March 2 (Xinhua) -- The U.S. Central Command announced on Monday the death of two additional U.S. service members in the attacks against Iran, bringing the total number to six.

"As of 4 pm ET, March 2, six U.S. service members have been killed in action. U.S. forces recently recovered the remains of two previously unaccounted for service members from a facility that was struck during Iran's initial attacks in the region," the command said in a post on X.

In another post earlier in the day, the command said the U.S. forces have sunk 11 Iranian naval vessels operating in the Gulf of Oman.

The United States and Israel began massive airstrikes against Iran on Saturday morning. Iran confirmed on Sunday that its Supreme Leader Ayatollah Ali Khamenei was killed in the airstrikes the previous day.

U.S. President Donald Trump said on Monday the military campaign against Iran has "capability to go far longer" than four to five weeks.

Democratic lawmakers have lashed out at the military operation, arguing that there was no imminent threat and the attack was not authorized by Congress.

Hakeem Jeffries, the top Democrat in the U.S. House of Representatives, wrote in a post on X on Sunday that he was "heartbroken by the loss of life of multiple service members in the Middle East."

"No more American heroes need to die because of a reckless decision to go to war. Congress must act this week to restrain this President," said Jeffries.