°®Âþµº

A leading al-Qaeda bomb maker is believed to have been killed, a US official told AFP on Tuesday, following a years' long hunt for the operative.

Ibrahim al-Asiri is wanted in relation to the Christmas Day 2009 bomb plot, when a Nigerian man attempted to set off plastic explosives imbedded in his underwear on a flight from Amsterdam to Detroit.

He is believed to have been on the run for years in Yemen, when he is thought to have been taken our a year ago.

"We are confident he was killed late last year," the official said on condition of anonymity.

According to a UN team that tracks terror groups in the Middle East, some Security Council members "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," notes the report, released last week.

The Pentagon said it had no information it could provide.

The Saudi militant was a member of the Yemen-based al-Qaeda in the Arabian Peninsula, which is one of the lead targets in US counter-terror operations.

Asiri, also known as Abu Saleh, was a one-time chemistry student on several most-wanted lists and had survived repeated US attempts to kill him.

He specialised in building non-metallic explosives, often using Pentaerythritol tetranitrate, or PETN, and chemical detonators.

He is also believed to have been behind the plot to send parcel bombs containing PETN hidden in printer ink cartridges from Yemen to Chicago in 2010.

Asiri is also believed to have designed a bomb used by his brother Abdullah, who died in a failed suicide attack on Saudi Arabia's deputy Interior Minister Prince Mohammed bin Nayef in 2009.