LONDON, March 2: The British police have launched a big investigating operation to trace the terrorists who have sent up to 16 packages containing a dangerous chemical, including two sent to the prime minister’s wife, Cherie Blair.

The suspicions are not centring on Al Qaeda or the Real IRA, a small dissident ultra-nationalist group that has been involved in a number of terrorists attacks in the recent years.

The police say they have received a call from a man claiming to be from the Scottish National Liberation Army saying 16 packages had been sent. But so far only two have been received, by Downing Street and an unnamed Scottish leader. Any others are expected to arrive later on Saturday.

The padded envelopes contained bottles purporting to hold eucalyptus oil but which really contained caustic soda which can cause serious injury and blindness. The package was addressed specifically to Tony Blair’s wife and ministers and political staff are being put on high alert as police fear they could be at risk of receiving further parcels containing a caustic substance disguised as eucalyptus oil.