The Italian Interior Ministry said on Thursday that it had stepped up security at potential terrorist targets following a major bomb plot alarm in Britain .
"Security at potential targets has been intensified, particularly regarding structures linked to the United Kingdom," the ministry said in a statement .
It stressed, however, that there were no "specific alarm signals" for Italy .
Premier Romano Prodi, who is on vacation in his home town of Bologna, said that "we are not taking any other special measures at the moment" .
"But it's clear that our guard remains high and it certainly won't be lowered in the future," the centre-left leader said .
British police said on Thursday morning that they had thwarted a plot to blow up several airplanes in mid-flight between Britain and the United States .
More than 20 suspects were arrested in overnight raids in and around London and Birmingham .
London Police Deputy Commissioner Paul Stephenson told reporters that "we are confident we have disrupted a plan by terrorists to cause untold death and destruction. Put simply, this was intended to be mass murder on an unimaginable scale" .
Sources close to the investigation said up to 10 planes had been targeted in the plot which was believed to involve an explosive liquid chemical .
Security has been beefed up at both British and US airports, causing massive delays and cancellations .
British carriers including British Airways and Virgin Atlantic banned hand luggage on flights, informing passengers that they were to pack all mobile phones, computers and handbags with their checked-in luggage .
Passengers were also banned from taking liquids on board except for essential medicines. Parents with babies were told that milk would be allowed providing they agreed to taste it in front of security officials .
The alarm caused havoc at Italian airports as well, with cancellations and long delays of flights to London .
British Airways urged Italian passengers to abandon or postpone any travel plans involving British destinations .
Security measures were also stepped up at Italian airports, with spot checks on passengers' hand luggage .
The Interior Ministry said it was not considering a hand luggage ban at the moment .
It said its anti-terrorism committee CASA was meeting on Thursday afternoon and that Interior Minister Giuliano Amato was "personally following developments" .
The scare sent shares down in Milan in line with other European exchanges. The bourse fell 1.06% in morning trading .
Shares in national flag carrier Alitalia tumbled almost 3% while insurance firms fell around 1% .
