Pakistan says it is still waiting for the British Government to explain reports that its London high commission was bugged by UK security services.
Scotland Yard could have been involved too, says Pakistan
British and Pakistani newspapers have alleged that contractors hired by MI5 planted bugs in the building in 2001.
Pakistan's Government says Scotland Yard, headquarters of the Metropolitan Police, may also have been involved.
A foreign ministry spokesman said Pakistanis were angry at the reports, and surprised by Britain's silence.
The BBC's Paul Anderson in Islamabad says the remarks are the strongest statement so far on the issue from the Pakistan Government.
Last week, it asked the UK Government for an inquiry into the reports.
'Angry and aghast'
"We would want a response because we believe that MI5 and Scotland Yard are not satellites above the British Government," foreign ministry spokesman Masood Khan was quoted as saying by the AFP news agency on Monday.
Islamabad also wants to know whether UK Home Secretary David Blunkett authorised the alleged bugging operation.
"They can determine very easily whether Mr Blunkett has given an authorisation or whether it was a rogue operation by MI5 or by Scotland Yard," Mr Khan said.
He said leading Pakistani figures he had spoken to were "aghast" that such an "espionage mission" could be conducted against a country with which Britain has close and friendly ties.
Mr Khan said Pakistan had increased security arrangements at its high commission in central London as well at its other consular offices in Britain.
It is carrying out its own investigation into the allegations.