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.

Hezbollah distributed new Gold Apollo pagers, believing them to be safe, only to have them explode and kill 37 people. The attacks, suspected to be orchestrated by Israel, also injured more than 3,000.

Hassan Nasrallah refused to say when or how Hezbollah would take revenge. As he spoke, Israeli fighter jets swooped low over Beirut.