The centres of Glasgow, Edinburgh and Dundee were partly evacuated after telephoned bomb alerts, all using acknowledged coded warnings, were received yesterday morning.
The warnings - clearly designed to cause maximum disruption - and the manner in which they were delivered to the authorities in all three cities, will now be examined in joint investigations by Strathclyde, Tayside, and Lothian and Borders police.
Police and bomb disposal experts were last night examining two 'suspicious devices' found at Glasgow's main sorting office in Paisley Road, and a third device found at the city's main post office in George Square.
A holdall containing inflammable material was also found in a left luggage locker at Glasgow's Central railway station. It was being examined last night to see if it was also a hoax.
In Edinburgh, police found packages at four post boxes and at a sorting office in Brunswick Street - all of them plain, unaddressed envelopes measuring eight by three inches. In Dundee, a Royal Navy bomb disposal team blew up a package found in a post box outside the Chamber of Commerce.
Assistant Chief Constable Peter Gibson, of Strathclyde Police, said they received a message at 10.30am that there were going to be three explosions in Glasgow's Central station, Bothwell Street and George Square. All buildings in those locations were evacuated for three hours.
The caller, who was male, gave no indication of the scale of the danger nor times of explosions. Mr Gibson said that the code used was 'one used by an individual or individuals rather than known organisations'.
Police said last night that nothing in their investigations had led them to believe any specific organisation was responsible.
In Edinburgh the hoax call caused chaos in the city centre around Hanover Street, Waterloo Place, Princes Street and the High Street.
In Dundee police carried out a controlled explosion in a post box near the city centre after a suspect package was discovered. Forensic scientists from Tayside Police were last night examining the remains.
All three cities were almost back to normal by late afternoon yesterday.
Police in Edinburgh were preparing for a major security operation tomorrow for the Scottish Conservative Party's three-day annual conference in the capital. Eight Cabinet ministers are attending. The Meadowbank conference centre is now likely to be the focus of a security clampdown.Reuse content