US officials say Ibrahim al-Asiri, an Al Qaeda bomb-maker believed to have masterminded a plot to down a commercial airliner over Detroit on Christmas Day 2009, was killed in a US drone strike last year, according to multiple reports.

Al-Asiri was described by a former US intelligence official, Michael Morell, as "probably the most sophisticated terrorist bomb-maker on the planet," CBS News reported Monday.

Morell, a former CIA deputy director, called al-Asiri's death "the most significant removal of a terrorist from the battlefield since the killing of [Osama] bin Laden."

Ibrahim al-Asiri, an Al Qaeda bomb-maker believed to have masterminded a plot to down a commercial airliner over Detroit on Christmas Day 2009, was killed in a US drone strike in Yemen last year, US officials confirmed to Fox News and CBS News on Monday.

Al-Asiri is said to have made the underwear bomb that a Nigerian man named Umar Farouk Abdulmutallab attempted to detonate on a Northwest Airlines flight to Detroit in December 2009. Al-Asiri was also involved in a plot to hide explosives in printer cartridges being shipped to the US. The first attack was unsuccessful because the attacker failed to detonate the device, and the other bombs were discovered after a tip.

Before his death, al-Asiri was believed to have been working on bombs that could be hidden inside laptops, CBS News reported.

Michael Morell, a former CIA deputy director, told CBS News that al-Asiri was a big reason for increased security at airports. "A good chunk of what you have to take out of your bag and what has to be screened is because of Asiri and his capabilities of putting explosives in very difficult to find places," he said.

Morell described al-Asiri as "probably the most sophisticated terrorist bomb-maker on the planet." He said in a tweet on Monday that it was "the most significant removal of a terrorist from the battlefield since the killing of [Osama] bin Laden."

Fox News reported that in 2009, al-Asiri hid explosives in his brother's clothes in an attempt to assassinate Saudi Arabia's interior minister; the brother was killed in the attack.

A report from the United Nations and statements from a Yemeni security official and a tribal leader had previously indicated that al-Asiri, a Saudi national and one of America's most wanted terrorists, was killed in a drone strike in the eastern Yemeni governorate of Marib, The Associated Press reported.

Al Qaeda's Yemeni affiliate has long been regarded as one of the most dangerous outfits, primarily because of al-Asiri's bomb-making abilities.