At least one gathering of senior officials and military leaders was hit, but it was not immediately clear whether the effort to kill them had succeeded.
The strike on an elementary school in the southern Iran town of Minab was one of two attacks that appear to have hit schools during U.S. and Israeli strikes on Iran on Saturday.
The notification stood in contrast to past military actions President Trump has undertaken unilaterally without consulting with Congress, drawing bipartisan anger.
Robert Jimison, Michael Gold, Julian Barnes, Eric Schmitt and Tyler Pager
Pakistan’s airstrikes in Afghanistan showed its overwhelming superiority in conventional warfare, but the Taliban have refined a lethal repertoire of guerrilla tactics.
Critics say the president is violating the Constitution, and many Democrats and at least two Republicans in Congress say they must vote on whether to enter such a conflict.
Iranians were beginning their workweek as U.S. and Israeli strikes sent people fleeing parts of the capital and parents racing to collect children from schools.
After blocking foreign oil shipments, the Trump administration is now allowing small amounts of oil to enter Cuba — as long as they circumvent government hands.