United Nations, Aug 17: The Al Qaeda's master bomb maker who was responsible for planning to blow up an airliner over Detroit on Christmas Day. may have been killed, according to a UN report.The UN report said that Ibrahim al-Asiri, long regarded as one of the most dangerous terrorist operatives in circulation, may have been killed in Yemen last year, CNN reported on Thursday."Since mid-2017, the organisation has suffered losses of leadership and field commanders owing to extensive Yemeni and international counter-terrorist operations," said the report by the UN's Analytical Support and Sanctions Monitoring Team. "Some member states report that explosives expert Ibrahim al-Asiri... may have been killed during the second half of 2017. Given al-Asiri's past role in plots against aviation, this would represent a serious blow to operational capability."The UN report gave no indication of how al-Asiri died or who may have been responsible and is the only public indication of his possible death. But multiple US officials told CNN that they were weighing evidence that al-Asiri is dead.Counter-terrorism analysts have said that there should be significant scepticism over al-Asiri's possible demise for one major reason: his group Al Qaeda in the Arabian Peninsula (AQAP) has not released any statement acknowledging his death, nor a eulogy celebrating his martyrdom.Aimen Dean, a former spy for British intelligence inside Al Qaeda, told CNN that until such a eulogy is released, al-Asiri should be assumed to be alive."It would be extremely out of the ordinary for them not do this for a senior leader like al-Asiri, especially because his group in Yemen are putting out all sorts of statements all the time," Dean said. "Every time a senior leader within Al Qaeda or its affiliate in Yemen has been killed, they have been quick to put out a statement."Al-Asiri is widely credited with perfecting miniaturised bombs with little or no metal content that could make it past some airport security screening. The son of a Saudi military officer, al-Asiri allegedly designed the so-called "underwear bomb" worn by Umar Farouk Abdulmutallab, a Nigerian who tried to blow up an airliner as it was landing in Detroit on Christmas Day 2009.