US 'foils new underwear bomb plot' by al-Qaeda in Yemen.

A plot by al-Qaeda in Yemen to detonate an upgraded version of the failed 2009 "underwear bomb" has been disrupted, BBC reported, citing US officials.

The device was seized by intelligence operatives and is in US custody undergoing technical and forensic analysis, the FBI said.

Reports said no target had been chosen and no plane tickets purchased by the time the alleged plot was foiled.

There is no indication on the status of the would-be bomber.

It is not clear who built the device, but officials say it shares some features with the bomb sewn into the underwear of would-be suicide bomber Umar Farouk Abdulmutallab.

He was arrested when his device failed to explode fully while on a plane bound for Detroit on Christmas Day 2009.

A US intelligence official said the latest device bore the "hallmarks" of the 2009 underwear bomb.

It included a powerful industrial explosive and did not use metal, suggesting the bomb could have passed through airport security unnoticed, the Associated Press reported.