Iranian top nuclear scientist and senior IRGC officer Mohammad Reza Sedighi Saber died in an Israeli airstrike on Tehran city, media reports said.

There has been no official confirmation on his death so far.

AI Researcher Eli David wrote on X: "Breaking: Mohammad Reza Sadighi Saber, one of Iran's top nuclear scientists, was eliminated."

"He survived the first elimination attempt 11 days ago, and fled to Astaneye Ashrafiyeh in northern Iran. He was eliminated there tonight," David said.

As per US State Department website, Sayyed Mohammad Reza Seddighi Saber is the head of Iran’s Organization of Defensive Innovation and Research’s (also known by its Persian acronym, SPND) Shahid Karimi Group.

The group works on explosives-related projects.

Seddighi Saber is linked to projects including research and testing applicable to the development of nuclear explosive devices.

Meanwhile, US President Donald Trump announces Israel and Iran have reached a ceasefire to end the 12-day fight.

Trump wrote on Truth Social, "CONGRATULATIONS TO EVERYONE! It has been fully agreed by and between Israel and Iran that there will be a Complete and Total CEASEFIRE (in approximately 6 hours from now, when Israel and Iran have wound down and completed their in progress, final missions!), for 12 hours, at which point the War will be considered, ENDED!

"Officially, Iran will start the CEASEFIRE and, upon the 12th Hour, Israel will start the CEASEFIRE and, upon the 24th Hour, an Official END to THE 12 DAY WAR will be saluted by the World. During each CEASEFIRE, the other side will remain PEACEFUL and RESPECTFUL."

Iran launched the Annunciation of Victory, a mission that was focused on Al Udeid Air Base as a counter to the US strikes, according to the Islamic Revolutionary Guard Corps.

"With the aggression of the American enemy, it became clear to everyone that the evil of the Zionists was an extension of the American design," the Iranian armed forces said in a statement.

"Accordingly, we remind you that in this national defense, the US mobile military bases and targets in the region are not a point of strength, but rather a major weakness and a blind spot for this war-mongering regime."

"Iran will not leave any attack on its territorial integrity, sovereignty, and national security unanswered under any circumstances," the IRGC statement said.

No casualties were reported in the airbase, US officials told reporters.

The attack on the Al-Udeid Air Base was "strongly condemned" by the Qatari government.

The attack comes after the US early on Saturday bombed Iran's three nuclear sites. The sites are Fordow, Natanz, and Esfahan.

B-2 bombers took off from Whiteman Air Force Base in Missouri in the early morning hours of Saturday (US time) to carry out the strikes.

The attack was carried out as the US joined the conflict that started a week ago when Israel launched airstrikes against Iranian nuclear and military sites, primarily targeting uranium enrichment facilities to prevent Iran from developing nuclear weapons.