Israel warned U.S. Defense Secretary Lloyd Austin in a call that a military operation was going to take place in Lebanon but gave no details, U.S. officials said.

The strikes come after Hezbollah's leader vowed to take revenge on Israel who it accuses of an audacious attack on pagers and handheld radios.

Amid fears of an expanding war in the Middle East following mass detentions of bombs surreptitiously planted in Hezbollah communication devices, Israel continued its assault of the Iran-backed militia overnight.