ANALYSIS-Pakistan's nuclear weapons are safe, for now

* Pakistan's nuclear installations seen secure

* Proximity and sophistication of Islamist attacks worrying

* Pakistan has multiple measures to guard nuclear weapons

* No outside power can remove them

By Myra MacDonald

LONDON, Nov 8 (Reuters) - Pakistan's nuclear installations are so well guarded that Islamist militants behind a wave of violence in the country's heartland would find it very hard to storm them and steal material for a nuclear bomb, analysts say.

But the sophistication of recent attacks and their proximity to Pakistan's nuclear infrastructure suggest this risk, while low, remains a cause for worry.

"I don't think it is realistic any more to say there is no threat to these weapons, that they are totally safe," said Professor Shaun Gregory at Britain's University of Bradford.