Lebanon's Hezbollah was still handing its members new Gold Apollo branded pagers hours before thousands blew up this week, two security sources said, indicating the group was confident the devices were safe despite an ongoing sweep of electronic kit to identify threats.

The president and founder of a Taiwanese pager company linked to the detonation of thousands of pagers targeting Hezbollah in Lebanon was questioned by prosecutors late into the night on Thursday, then released.

Israel’s operation against Hezbollah members in Lebanon and Syria through booby-trapped pagers and walkie-talkies was years in the making, and its use now ramped up a high-risk campaign aimed at deeply disrupting the group.

Hezbollah and Israel have traded blows in recent days, as the conflict has escalated with few off-ramps in sight to avoid total war.

Israel launched a rare airstrike that killed a senior Hezbollah military official in a densely populated southern Beirut neighborhood on Friday. It was the deadliest such strike on Lebanon’s capital in decades,