The decision was announced at an emergency meeting of the organisation's foreign ministers in London.

Ministers have called on the military regime in Islamabad to set a timeframe for the restoration of a democratic government in Pakistan.

The ministers will send a mission to meet the military leaders to press for the return of civilian rule.

The measure is more of a symbolic gesture than one with practical consequences.

However, other sanctions are likely to follow - from the US, Europe and the International Monetary Fund - and their impact on Pakistan's already virtually bankrupt economy would be much more serious.

Chief-of-staff General Pervez Musharraf assumed the position of chief executive on Thursday night after ousting Prime Minister Nawaz Sharif.

Mr Sharif remains in "protective custody" at an undisclosed location.