Israel’s spy service injected explosive materials activated by coded messages into thousands of Gold Apollo-branded pagers during production, months before they were imported imported by the Lebanese group Hezbollah, a senior Lebanese security source said. Hezbollah fighters were using the low-tech devices in an attempt to evade Israeli location-tracking, sources said. For its part, Taiwan-based Gold Apollo said it had not manufactured the devices used in the blasts, but that they had been made by a European firm with the right to use its brand.