Some analysts have raised fears that instability following Bhutto's killing Thursday could lead to unrest which would open the door for weapons to fall into the wrong hands.

Professor Paul Wilkinson, chairman of Saint Andrews University's Centre for the Study of Terrorism and Political Violence, said that Western nations "really ought to be concerned" about this "nightmare scenario".

"We could have a situation where extremists were able to control the nuclear facilities of Pakistan," he said.

"That would be a very dangerous, nightmare scenario and one that we really ought to be concerned about."

But Christian Le Miere, managing editor of Jane's security journal Country Risk, said that Pakistan's nuclear capacity "remains strongly in the hands of the military".

He suggested that Bhutto's death would not seriously affect this.

"The issue is cash -- if a scientist or...a group of scientists decide that their income is too low, they could go on the black market to offer material, that's the main danger," he said.

"They have still scientists out there that could pass information to the black market or hand over nuclear material to a state, in order to supplement their income."

He predicted that the military would step up security around facilities in the wake of Bhutto's death.

The former prime minister was killed in Rawalpindi and was buried alongside her father in southern Pakistan on Friday.

All rights reserved. © 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.