WATCH: Pentagon holds news briefing as Hezbollah leader says pager attack crossed ‘red line’

The Pentagon held a news briefing on Thursday as the leader of Hezbollah said this week’s deadly attack on the Lebanon-based militant group’s communications devices was a “severe blow” that crossed a “red line.”

Watch the briefing in the player above.

Hassan Nasrallah said the group is investigating how the two-day attack, which killed more than 30, wounded thousands and was widely believed to be carried out by Israel.

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“Yes, we were subjected to a huge and severe blow,” Nasrallah said. “The enemy crossed all boundaries and red lines,” he added.

As usual, Nasrallah spoke by video from an undisclosed location. Hezbollah typically convenes a rally for supporters to watch his speeches on a big screen, but this time they did not.