WASHINGTON, April 9: Al Qaeda planner Abu Obaidah al Masri — a main suspect in the 2005 London subway and bus bombings and a foiled 2006 plot to blow up passenger planes — is believed to have died of natural causes, American and British officials said on Wednesday.

“There is compelling reason to believe that Abu Obaidah is dead,” a US counterterrorism official said on condition of anonymity. McClatchy newspapers reported that Masri died of hepatitis in Pakistan.

The US official said Masri appeared to have died of natural causes, and a British official said his death had been known to security sources for some time.

“He was a major operational figure,” another US official said of Masri.—Reuters