Several more troops were wounded as part of the U.S. and Israel effort against Tehran.

Three U.S. troops were killed and five more “seriously wounded” as part of the joint U.S.-Israel operation targeting Iranian military sites and government officials, according to U.S. Central Command, marking the first American deaths in the conflict.

Several other troops “sustained minor shrapnel injuries and concussions,” the command said Sunday, without giving a location. Iranian missiles have targeted some American bases in Bahrain, Iraq and Kuwait as part of the conflict, which the Pentagon has dubbed Operation Epic Fury.

These are the first confirmed U.S. fatalities since President Donald Trump announced Saturday that the U.S. had begun “major combat operations” in Iran. And they dramatically raise the stakes. The fatalities are likely to intensify pressure on the White House and the Pentagon to respond forcefully, potentially widening the conflict beyond limited strikes into a more sustained military campaign.

Confirmed American deaths also represent a significant break from the recent pattern of calibrated, contained escalation.

The operation — described by Trump as a necessary blow against Iran’s military and nuclear infrastructure — had already pushed the longtime adversaries into their most direct confrontation in years.

Iran has launched “hundreds” of ballistic missiles and drones at American forces in the region since the American and Israeli strikes began, according to a U.S. official, most of which were intercepted by air defenses. The person was granted anonymity to discuss a sensitive topic.

Iran said it has retaliated against U.S. military facilities in several countries in the Persian Gulf, as well as launched barrages of missiles toward Israel. These include Al Udeid Air Base in Qatar, Ali Al Salem Air Base in Kuwait, Al Dhafra Air Base in the United Arab Emirates and the U.S. naval base in Bahrain.

Muwaffaq Salti Air Base in Jordan was also targeted, according to Iranian state media, as well as a U.S. base in northern Iraq.

Democrats quickly put the onus on the president.

“He tries to pass it off as if it’s like ’oh, we’re at war, and it’s terrible that servicemembers might be killed,’” said Sen. Andy Kim (D-N.J.). “He is choosing this. He put [U.S. troops] in harm’s way. They didn’t have to die.”