The U.S. military struck targets in Iran near the Strait of Hormuz in what a spokesman for the military said Monday were acts of self-defense.

Axar.az reports that, citing NBC news, Navy Capt. Tim Hawkins, a spokesman for U.S. Central Command, said the attacks were “self-defense strikes” and included “missile launch sites and Iranian boats attempting to emplace mines.”

The strikes were in Bandar Abbas, in southern Iran, near the Strait of Hormuz, a defense official said.

There was no announcement of any change in the temporary ceasefire between the U.S. and Iran, which went into effect April 8.

“U.S. Central Command continues to defend our forces while using restraint during the ongoing ceasefire,” Hawkins said.

Iranian media later reported that members of the Islamic Revolutionary Guard Corps suffered casualties in the strikes.

According to the reports, four IRGC members were killed in the attacks.