The U.S. military announced Sunday that it had recovered unidentified human remains while searching for an American service member reported missing after an Iranian missile and drone attack in Jordan, as another U.S. service member was killed in a separate incident in Iraq.

U.S. Central Command said military personnel found the remains Sunday at the site of Friday’s attack in Jordan. Officials said an examination is underway to determine whether they belong to the missing service member.

The announcement came a day after CENTCOM said two U.S. service members were killed and a third was missing following Iran’s Friday attack on U.S. and partner forces in Jordan.

Separately, CENTCOM said a U.S. service member was killed Saturday in northern Iraq during the controlled detonation of unexploded ordnance from a downed Iranian one-way attack drone. A second service member suffered a minor injury and remains under medical care.

“Our hearts go out to these families,” Secretary of State Marco Rubio told reporters Sunday. “These are heroes that pay the ultimate price.”

The mounting death toll has effectively ended the interim ceasefire between the U.S. and Iran negotiated last month. After weeks of trading accusations that each side has violated the agreement, the two countries resumed attacks, with U.S. forces striking Iranian military targets and Tehran launching missiles and drones at U.S. allies in the region.

Rubio said the U.S. remained open to diplomacy with Iran, but that “even within their own system, there’s a growing split.”

“They continue to send signals that they want to talk, that they want to negotiate,” he said. “But their behavior is what we’re responding to, and their behavior is they’re launching missiles and drones against ships, including tonight.”

“Their behavior has to change in order for ours to change,” Rubio added.

On Sunday evening, CENTCOM said it conducted a ninth consecutive night of attacks on Iran starting at 7 p.m. ET. It said in a subsequent statement shortly after 10 p.m. ET that the strikes had concluded.

“CENTCOM assets targeted Iranian military command centers, air defense and coastal surveillance sites, maritime capabilities, missile and drone launch sites, and communications networks to further diminish Iran’s ability to attack commercial vessels and civilian mariners transiting the Strait of Hormuz,” it said.

On Saturday, the command said U.S. forces completed the eighth night of launching munitions against Iran when it targeted Islamic Revolutionary Guard Corps forces believed to have been involved in Friday’s attack on U.S. service members in Jordan.

The military said that the two service members who were killed died while defending against an Iranian ballistic missile and drone attack. Four other U.S. service members were medically evacuated to hospitals in Jordan, but have since been discharged.