For a man reputedly at the forefront of al-Qaeda's global terror operations -- with one finger in plots to target the US and another in attempts to assassinate Pakistan's president -- Hamza Rabia kept a remarkably low profile.
The Egyptian wasn't on the FBI's list of the world's 15 most wanted terrorists, nor had he made Pakistan's most wanted list. In fact, there had been little public mention of Rabia before he was apparently killed last week in an explosion at his tribal hideout.
US officials haven't confirmed the death, despite claims by Pakistani President Pervez Musharraf that he is ``200 percent'' sure Rabia died. Yet officials in Islamabad and Washington have been quick to agree that Rabia's demise would be a major blow to Osama bin Laden's terror network, saying he ranked in the top five of its hierarchy.
US National Security Adviser Stephen Hadley described Rabia as al-Qaeda's head of operations, adding in an interview with Fox News Sunday that ``we believe he was involved in planning for attacks against the United States.''
How could a man apparently so powerful, in such a critical position, escape attention for so long?
Skeptics are demanding more information about Rabia's role in alleged plots, and pointing to what they see as a troubling trend in Pakistan and the US of hyping counterterrorism successes that may not be as big as claimed.
"He may be a serious planner that has been lurking in the shadows, but I would like to see more evidence of his terrorist credentials before saying he's a particular number in the hierarchy. I think these are relatively low-level operators," said Magnus Ranstorp, a terrorism expert at the Swedish National Defense College, referring to Rabia and his associate, Abu Faraj al-Libbi, who was captured in Pakistan in May.
Pakistan says both men had a hand in twin attempts to assassinate Musharraf in December 2003.
Information Minister Sheikh Rashid Ahmed said that Rabia was al-Qaeda's No. 5 leader. Two US counterterrorism officials, who spoke on condition of anonymity because of the information's sensitivity, said he was possibly as high as No. 3, just below bin Laden and his lieutenant, Ayman al-Zawahri.
But Paul Wilkinson, a terrorism expert at the University of St. Andrews in Scotland, said Rabia appears to have been more of a ground commander, not a key international terror mastermind.
Ranstorp said he feared the story was being touted in Washington and Islamabad for political reasons.