Hezbollah pounded northern Israel with 140 rockets Friday, a day after the militant group’s leader Hassan Nasrallah vowed to retaliate against Israel for a mass bombing attack, the Israeli military and the militant group said.

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

The Hezbollah leader, Hassan Nasrallah, did not say how his group would respond to attacks on hand-held devices, which killed dozens when pagers and walkie-talkies exploded.