State Department tells Americans worldwide to 'exercise increased caution'

More than a dozen unmanned MQ-9 Reaper drones have been lost in combat as part of the operations against Iran, two U.S. officials confirmed to ABC News.

The Reaper drones were either lost to Iranian missile fire or were destroyed on the ground by incoming fire.

Reaper drones can be used as reconnaissance aircraft, but they are also equipped with Hellfire missiles used to strike at targets.

The loss of this number of Reapers is indicative of how many of these key unmanned aircraft must be operating as part of the U.S. operations against Iran.

The loss of the drones in the Iran war was first reported by the Wall Street Journal.

The Islamic Revolutionary Guard Corps confirmed that Basij commander Gholamreza Soleimani has been killed in an "Israeli-U.S. attack."

In a statement on Tuesday, the IRGC said that Soleimani's assassination shows "importance and role of the Basij" in the fight against Israel and the United States.

The Israel Defense Forces said on Tuesday they are deepening their position into Southern Lebanon, claiming they are creating "additional layer of security for residents of northern Israel."

"In recent days, IDF troops from the 36th Division have begun limited and targeted ground operations aimed at enhancing the forward defense area," the IDF said in a statement.

"The troops are continuing efforts to establish the forward defensive posture in order to remove threats and create an additional layer of security for residents of northern Israel," the IDF said.

The Israel Defense Forces claimed, without evidence, that Hezbollah is planning for an attack against Israel, including rocket barrages, in the coming hours, according to a statement.

In a letter addressed to Hezbollah fighters, Hezbollah Secretary-General Naim Qassem praised them and pledged to continue fighting on Tuesday.