Israeli Prime Minister Benjamin Netanyahu delivers a statement to the media at the Defence Ministry in Tel Aviv, Israel December 4, 2018. REUTERS/Ammar Awad

JERUSALEM (Reuters) - Israeli Prime Minister Benjamin Netanyahu said on Tuesday that the Iran-backed Shi’ite militia Hezbollah had dug cross-border tunnels from Lebanon to insert militants into northern Israel.

Netanyahu spoke after the Israeli military said earlier in the day that it had launched an operation on the Israeli side of the border to “expose and thwart” the underground activity.

Netanyahu said Israel took the decision to act against the tunnels “weeks ago” and moved into action on Tuesday morning. He said the operation would continue as long as necessary and was a “small part” of a deployment on all fronts to defend Israel.