Hezbollah leader Hassan Nasrallah said Thursday that Israel’s deadly pager and hand-held radio attacks that targeted his fighters across Lebanon amounted to a “declaration of war,” calling it a “major aggression” against his people.

Hezbollah was hit by another wave of attacks Wednesday, killing 20 people and injuring more than 450, according to health officials, as walkie-talkies used by the group exploded across Lebanon.