BEIRUT: Lebanon’s Hezbollah was still handing its members new Gold Apollo branded pagers hours before thousands of the devices this week, two security sources said, indicating the group was confident they were safe despite an ongoing sweep of electronic equipment to identify threats. One member of the Iranian-backed militia received a new pager on Monday that exploded the next day while it was still in its box, said one of the sources. A pager given to a senior member days earlier injured a subordinate when it detonated, the second source said. In an apparently coordinated attack, the Gold Apollo branded devices detonated on Tuesday across Hezbollah’s strongholds of south Lebanon, Beirut’s suburbs and the eastern Bekaa valley. On Wednesday, hundreds of Hezbollah walkie-talkies exploded. The consecutive attacks killed 37 people, including two children, and injured more than 3,000 people. Lebanon and Hezbollah say Israel was behind the attacks. Israel’s secretive military intelligence Unit 8200 was involved in the planning, a Western security source said this week. Israel, which has since stepped up air strikes on Lebanon, has neither denied nor confirmed involvement. The batteries of the walkie-talkies were laced with a highly explosive compound known as PETN, another Lebanese source familiar with the device’s components said on Friday. Up to three grams of explosives hidden in the pagers had gone undetected for months by Hezbollah. One of the security sources said it was very hard to detect the explosives “with any device or scanner”. The source did not specify what type of scanners Hezbollah had run the pagers through. Hezbollah examined the pagers after they were delivered to Lebanon, starting in 2022, including by travelling through airports with them to ensure they would not trigger alarms, two additional sources told Reuters. In total, Reuters spoke to six sources familiar with the details of the exploding devices for this story. The sources did not specify the name of the airports where they conducted the tests. Rather than a specific suspicion of the pagers, the checks had been part of a routine “sweep” of its equipment, including communications devices, to find any indications that they were laced with explosives or surveillance mechanisms, one of the security sources said. The attacks, and the distribution of the devices despite the routine sweep and checks for breaches, have struck at Hezbollah’s reputation as the most formidable of Iran’s allied `Axis of Resistance’ umbrella of anti-Israel irregular forces across the Middle East. In a televised speech on Thursday, Hezbollah Secretary General Hassan Nasrallah said the attacks were “unprecedented in the history” of the group. Hezbollah’s media office and Israel’s armed forces did not immediately respond to requests for comment for this story. Taiwan-based Gold Apollo has said it did not manufacture the devices used in the attack, saying they were made by a company in Europe licensed to use the firm’s brand. A batch of 5,000 pagers was brought to Lebanon this year. Hezbollah turned to pagers to evade Israeli surveillance of its mobile phones, following the killing of senior commanders in targeted air strikes over the past year.