And where is that supposed terrorist den situated?
We can base our security plans on M15's models.
For that we need MI5 like resources and Scotlandyard trained police officers. We can't expect MI5 like performance from security officers who are under-trained, underpaid and not sufficiently armed to defend themselves.
The other approach to tackle suicide attacks, which Americans have adopted in Afghanistan & Iraq, is to shoot "suspects" from a safe distance. This approach can not & must not be adopted in Pakistan.