ABC's Simon McGregor-Wood reports from Jerusalem: Israeli intelligence company monitored web discussions about plane bombing tactics weeks before the Detroit attack. Most of the analysts at Terrogence are former Israeli intelligence operatives. From a converted chicken coop in a village in central Israel they monitor Islamic internet sites devoted to global jihad and terrorism. Their mission is to identify new and credible threats against western targets. They told ABC News Monday that as early as September they picked up detailed conversations on one of the most popular Islamic forums about how to bring down planes using so-called “improvised detonation chain” devices, exactly like the one used by Umar Farouk Abdulmutallab on Christmas Day. According to Terrogence founder Gadi Aviran the online discussion ran to 25 pages and continued until a critical posting in late November by a known extremist with a proven track record in explosives. This individual has been monitored for several years and is widely respected by participants in the forums. His posting in Arabic read: “You can ignite a detonator using a medical capsule and put concentrated sulphuric acid into it, and then put it over the explosive materials.” They believe the “medical capsule” mentioned in the post could easily refer to a syringe as used in the attack on North West Flight 253. Earlier, activists had detailed debates about how much chemical to use to avoid detection in airports and which liquids work best as a detonator. After this posting Terrogence sent warnings to their clients around the world which include so-called “Western governmental agencies." The online discussion was not specifically about plans to attack the Detroit bound flight but it showed that the technique used was being debated widely and in great technical detail weeks before. In the same forum a chilling discussion was held about the use of biological agents on passenger jets, including deadly Botulinum toxin carried in aerosol cans. This so-called “thread” of postings from the same extremists also showed great levels of technical expertise and knowledge of chemical and biological agents. Gadi Aviran believes this biological threat to be credible and has sent similar urgent warnings to his clients. After the Christmas Day attack the forums have posted messages congratulating Al Qaeda and an online debate has already started on how to defeat new security measures that western airports are going to introduce.